Then it's down the gold-balustraded, Hollywood-style staircase hung with poster-sized photographs of his beautiful clients beautifully coiffed - "Hello, Jemima ... Hello ..." - and into the VIP room. Here, it is explained, the likes of Anthea Turner can have their hair done without being gawped at by the Essex girls who have saved up for the last year (or two) to be Nicky Clarked.
No, I'm told, I can't just potter about the salon. Yes, Nicky's about somewhere, but he's attending to a client. No, I can't chat to him as he snips, teases, sprays and goes "whoosh" on one of those great stools that revolve like a funfair ride around the client's chair. A Nicky Clarke hairdo costs pounds 250. (Plus pounds 1.75, should you want a cup of tea while he's going about it.) He has to concentrate. It wouldn't be fair on the client if he were distracted. Wait here, if you will, and he'll pop in between clients to talk to you. Yes, he is very much like royalty himself these days, isn't he? Although, that said, no, a curtsy will not be necessary.
The VIP room is very posh. There are more photographs, only this time they are signed ones. There's Julia Carling ("To Nicky, it's all the rage"); the Duchess of York ("Sarah, 1994"); and the Linleys ("To Nicky, with love Serena and David"). There's also a copy of the Duchess of York's autobiography, My Story, knocking about. "To Nicky and Lesley," the Duchess has written on the flyleaf, "Happy Christmas, 1996, love Sarah."
As I wait, I start to read. There's not much else to do, after all. I am just up to the bit where she is trying to explain away the toe-sucking - "John Bryan and I were actually playing at Cinderella when the picture was snapped, the whole scene was not nearly as intense as it looked" - when, irritatingly, Nicky bounds in, shaking his own hair like some pedigree Afghan hound.
"Have you read this?" I ask, holding up the book. No, he confesses, he hasn't. But that's because he is not a great reader. "I would love to tell you I'm into Dostoyevsky," he says, "but I'm not."
He is, however, very into Gucci. Today, it is a Gucci black shirt, Gucci brown leather trousers, Gucci gold-buckled shoes and something black, diaphanous and Gucci tied artistically around his neck. "I seem to like what Gucci are doing at the moment," he explains.
He is 38 and quite attractive in a girlish way. I don't mean he's camp or effeminate, just that he's delicate-featured, with fair skin, strawberry blond shoulder-length hair and little peaky bits of sideburn. Should you ever have had an erotic dream about any of the Bee Gees, say, I imagine Nicky pretty much does it for you.
Does he think of himself as good-looking? "I do what I can. If my weight goes up I bring it down. My only bad habit is the odd cigarette. Can I have one of yours?"
I wonder, does he ever feel bad about charging so much for a hairdo? No, he says, he does not. "In fact," he adds cheerfully, "I am seriously considering putting the price up. Actually, I could probably charge double and still get away with it." What, pounds 500? "Yes, but I won't because even I can't get my head round that.
"Look, why do I charge what I do? Basically, because I can. If one company thinks they do a job better than another, they charge more, don't they? If you don't want to pay it, then don't buy it."
Certainly in Nicky's case lots of people do want to buy whatever it is he offers. He will take only 12 weeks' worth of bookings in advance. Then, on Monday mornings at 8.30am, the salon starts taking bookings for the 13th week. Usually all these appointments are gone by 8.45am, "although six minutes is our record".
Is he really better at what he does than anyone else? Certainly, many think so. As it is, his PR person is darting about waving a fax from Patti Lupone, who's in town and requires his attention. "Yes, of course I'll squeeze her in. I love Patti."
Once he was summoned to Paula Yates while she was in labour in hospital. "Bob phoned me at home at 6am. `Get down here. She needs you,' he said. By the time I got to the salon he'd phoned again twice. "For fuck's sake, get down here or she's never going to have the baby,' he shouted." Nicky went. Paula told the hospital staff to unplug the foetal heart monitor so Nicky had somewhere to plug his hairdryer in.
So, yes, he is probably a very good hairdresser. But that does not, of course, entirely account for his appearances on This Morning, or for the fact that Liam Gallagher drops in. "Yeah, Liam was round the other day. He really liked my John Lennon lithographs, which I bought in New York about 10 years ago. Then he saw I owned the complete Beatles collection, and we bonded a little bit there."
The thing about Nicky is that he's always been in the right place at the right time. He's never had to backcomb OAPs in some back-street salon. At 16, he got a job at Leonard's, the most swinging salon of the Sixties. When he and John Frieda left Leonard's, they took a substantial portion of the client list, too. In short, Nicky has always attended to the famous. And once you make one famous person look nice, other famous people pile in.
Plus, of course, there is Lesley. She is Nicky's wife, and she manages the business side of Nicky Clarke. Lesley used to be a designer, but she has a degree in mathematics and, apparently, a mind like a nail.
It was Lesley who encouraged Nicky to go it alone, and raised the money for him to do so. "She went into the bank with this fucking good business plan," he enthuses.
Lesley's about somewhere - probably up in the office doing nasty sums. I say she has always sounded rather scary in a Lady Macbeth sort of way. Nicky looks aghast, then he cries: "But she's a sweetheart."
Sweetheart or not, current tabloid gossip has it that the two separated several months ago, and now live apart. When I ask him about this, he gets shirty. "I take the stand this is not something I have to discuss," he says. "I know what our situation is and it's very personal."
Nicky and Lesley preside over a substantial business empire. It wouldn't do to expose rifts.
Anyway, he must now go back out to check on his client. He is gone for a long time. So I go back to My Story.
Nicky was born to an English father and a Greek Orthodox mother. His parents had met during a war, in Athens, when his father, an electrical engineer, was in the army. Nicky is not sure if it was the Second World War or some kind of civil war: "I'm not very up on my political history." Anyway, they fell in love, married, then came to England, where they settled into a two-bed, no-bathroom terraced job on the Old Kent Road and had six children.
Yes, it was overcrowded. "The council were always throwing their hands up in horror." But, still, "I had a brilliant childhood." Like all his siblings, Nicky attended the local grammar school. "We were a very academic family. I have a sister with a first-class degree." However, he got only two O-levels, English language and literature. He was never academic himself, he says.
By this time he'd already decided he wanted to be a hairdresser. When he was 12, his father had sent away for a 12/6d barber's kit, as advertised in the Daily Mirror. Pretty soon Nicky was doing all the cutting. Why, though? "Because it was the late Sixties, early Seventies, and everyone was very fashion-conscious. I wanted to be creative, and started playing with hair. At 14, I was giving my friends very funky cuts."
After training at Leonard's, he left with Frieda when it became obvious that the shop was going into decline. "Leonard was great. Very generous, very inspirational. But it got to the point where he just wasn't around much any more. He was too busy having lunch with Tony Curtis."
He and Frieda decamped to a little shop off the Marylebone Road with Leonard's files and appointment sheets. All they had to do was ring up: "Hi there, Mrs Joe Blow, just wanted you to know my new address" - and they were in business. It wasn't pleasant, says Nicky, but it was real life.
Eventually, Nicky became Frieda's chief oppo in a swish new salon in New Cavendish Street. Here, among other looks, they created the Purdey cut, as sported by Joanna Lumley in The Avengers.
"We did it, yeah," Nicky owns up. "Well, John did it when I was his assistant. The first cut, though, was very straight, but had movement. The fact that it became a huge bowl had nothing to do with us."
In the late Eighties, Nicky and John had a falling-out. It was something to do with Frieda promising Nicky a share of the business, then allegedly reneging on the deal. Nicky took him to court. Frieda settled out of court. The two are on speaking terms again, but will never be bosom pals as they once were. When I ask him if Frieda does Norma Major's hair, he says, disdainfully: "I think someone at John Frieda does it."
I'd read somewhere that at some point in the early Eighties he spent two months in a drugs clinic coming off heroin. "That," he says, getting shirty again, "is something I have never discussed and will never discuss." OK, then. But will you tell me how the experience changed you? "No. If I do that, I'll be accepting it's true." If Nicky were indiscreet about himself, his clients might not trust him. Nicky knows this.
So I change the subject. He must be very rich, I say. He owns, aside from all the Gucci, two swanky houses and a swanky car, and his two children attend private schools. Yes, he replies, he is quite well off, thank you.
I wonder if he has decided who he is going to vote for, come the election. "Oh, I'm a staunch Tory," he says. Socialism, he continues, is like Communism. "It looks OK on paper, but it's a crummy system that don't work. And you have to have entrepreneurs to provide the backbone of the country. Yes, of course you want everyone to have the same educational opportunities but ... look, I'm just a hairdresser, for fuck's sake. I'm not a political theorist."
Who in the public eye would he most like to get hold of? Well, Blair would be good. Tony? No, Lionel. "I met him at a party recently. He said I could make him over, but it hasn't happened, yet."
He would also like to have a word with the Charlton boys about all that sweeping of hair over bald bits. "It actually makes them look older," he cries. "Now, I'd better get out on to the floor or I'll be lynched."
I have finished My Story by the time he next reappears, so am inspecting the Duchess's photograph on the cover. Fergie, I say, used to have bushy, frizzy hair, but now it's all sleek. How come? "Lots of blow-drying; lots of product," he says.
Ah, product. Nicky has his own product range. Hairomatherapy, it's called, and it's worth pounds 5m a year. No, Nicky Clarke products are not simply endorsed by him. He and Lesley created them from scratch, in conjunction with chemists. Product is fantastic stuff, he says.
Do I use product? he asks. No, I'm afraid not. I am a Wash 'n' Go sort of person, I say. Mostly, I find it a job to remember to get dressed in between. Nicky goes "humph". I say I can't remember the last time I went to a hairdresser. Mostly, I keep my fringe in trim by singeing it every time I light a fag off the gas cooker. Nicky goes "humph" again. It saves me a fortune, I add. Nicky says he can see how it would.
So, Nicky, I finally ask while giving him my loveliest smile, what would you do to my hair? He just says, "I don't know. I'd have to have a good look at it."
All in all, he took four cigarettes off me and never gave me a single hair tip. But it wasn't an entirely wasted six hours. I got to read My Story, which saved me pounds 15.99.