Having actually been born in Bow, I'm surprised that nobody has mentioned Harry Champion the music hall artist. In his song "Boiled Beef and Carrots" he included 'that's the stuff for your Derby Kell
Derby Kelly = Belly), makes you fat and keeps you well'. And of course his probably most famous song "Any Old Iron" the title of which refers to an 'Iron Hoof' = Poof (or Faggot for your transatlantic readers).

My father used rhyming slang quite a bit in his normal everyday speech, I was often told as a God Forbid (kid) to "hold your box of toys" normally shortened to "Hold yer boxer" if I was making too much noise.

The practice did seem to be dying out and I believe has only re-appeared due to TV soaps where I believe much of it was made up by script writers rather than taken from the tradition. I think for instance that Irish (Irish Jig) for wig makes more sense than Syrup (of Figs). And might I add Beer has always been Pig's Ear.