Ah, a sensible addition to this thread, which was lurking in the back of my head, has just revealed itself.

Years ago, I was playing with a real leather-and-grime rock lead guitarist, whose general image was about as daisy-fresh as those guys on the American wrestling programmes. One day I caught him in the dressing room just before the show, carefully doing his hands in 'Mother's Favourite Dandelion' or some such unlikely soap. He told me that the best tip he had ever been given for playing guitar fast and clean was to learn how, and when, to wash your hands thoroughly before going onstage. (The importance of the 'when', of course, was so that your hands aren't still too soft when you start playing.)

- IanB