Steve Martin communed with his nose in Roxanne, Michael Caine lectured his severed fingers in The Hand, and in the upcoming Me and Him Griffin Dunne chats up his penis. But not until this vigorous, cheerfully outrageous British satire has a character ever argued with a nasty boil on his neck. Worse, the boil sasses back.

The pustule in question has risen on Dennis Bagley, a London advertising whiz who harvests a fortune for his clients by playing on the public's fear of dandruff, piles, bad…