Cor blimey! Cockney rhyming slang may have originated as a cryptolect to confound outsiders, occasionally including the law. If so, it failed, as most of it is widely understood far beyond Bow Bells.
Indeed, many expressions have long since lost their link to the rhymes whence they came, such as rabbitting for talking (rabbit and pork), Hampton (from Hampton Wick, no further explanation necessary) and "a butchers" (butcher's hook, look).
The magnificent "syrup", for wig, seems to be on the verge of breaking through to the mainstream (it derives from a fairly archaic cure for constipation, syrup of figs).
Rhyming slang can work especially neatly when the words or phrases are fitting, such as "strawberry", for heart (from strawberry tart), "bag for life" (wife) and the new Euan Blair (Leicester Square).
Whether you choose to term your pain in the Aris Emmas (Emma Freuds, haemorrhoids) or Chalfonts (Chalfont St Giles, piles) is up to you, me old china (china plate, mate).