Local papers are usually the best source for such jobs. Though if you are sufficiently motivated, there's nothing at all wrong with asking. It shows initiative. A 'phone call might save you a lot of walking.
You might consider a bit a flexibility; you mentioned bar/waiting on work, but there's other work in pubs & restaurants. You might have to start with something else first. Having done it, I can tell you washing pots isn't as bad as it sounds, in fact it's relatively easy work.