Dom Joly: When disguise is more than just making others laugh

I'm back from Canada and straight into filming. It's all is a bit of a shock to the system when you've been in Politeland for a month. Over there, the only stress is having to say hello and smile at everyone you pass by (it'll soon pass, now I'm back, but it always takes a while to start scowling at everyone again).

I'm doing some hidden-camera filming and for this I need a decent disguise. So, almost straight off the plane I get whisked around Greater London building up my new identity. First, I get some false teeth made, then it's off to the nose shop to have a prosthetic one modelled. After that, it's a trip to one of the huge costume departments that sit in weird moth-free warehouses dotted around the city. Finally, I popped over to the East End for a wig fitting.

It's an extraordinary thing to be able to have all these incredibly talented people turn you into somebody completely different. I once turned myself into an 77-year-old man who looked a little like Alan Whicker and then knocked on my mother's door, pretending to canvass for the BNP. She didn't recognise me but, thankfully, sent me away with a flea in my ear.

Having things like false teeth really help you talk and sound very different, but you're constantly aware that the joins in your nose can start to lift, your teeth might come loose or the edges of your wig start to show. For me, it's important to stay properly disguised because I want to be able to fool someone and, hopefully, do something funny.

For others, it's a little more important. I'm doing an occasional podcast at the moment and this week, among others, my guest was Howard Marks the ex-international drug smuggler turned weird stoned national treasure. In his time, Howard was also a bit of a master of disguise. He used 43 different aliases, several passports and a multitude of disguises. At one time he was supposed to be in charge of 10 per cent of the world's hashish trade – this while eagerly consuming as much of his product as possible. He told me about his most traumatic experience: it involved somebody smuggling in several tabs of acid when he was in solitary confinement in prison in Indiana.

With no hallucinogenic assistance whatsoever, it's still very weird when you catch sight of your reflection – it's a little like finding yourself trapped in one of those Hollywood "people-swap" movies. On the inside you feel exactly the same, but the person staring back at you is not you and it's a tad freaky. The idea of doing this on drugs while in solitary confinement or when having to wander through immigration sends me crazy just thinking about it.

I wonder what the deal is with that kind of thing. Presumably it's illegal to disguise yourself and attempt to go through passport control. What does Elton John do? If his passport photo has him without his wig, then surely he has to travel like that. If he doesn't, then his passport photo is of him wearing a wig and is therefore illegal and he should be arrested and, at the very least banned from the London passport office, as I am (for having an "attitude").

I'm obsessed now – just how does Elton John travel? Even a private jet must go through passport control. Maybe his passport photo has that picture of him dressed as Donald Duck playing the piano and he has persuaded Louis Vuitton to make matching duck luggage for him. Maybe he travels as a duck. How do I get a copy of Elton's passport photo?

This is the sort of important thing WikiLeaks should be providing...