I know with most weird accents, translators will try to choose a dialect that reflects that. But it has it's issues. My favorite example has always been that Goku from Dragonball speaks the Japanese equivalent of a redneck yokel accent. So obviously, it had to be something different, since the implications of a country boy are different in Japan and America.

If there's really no good way to translate it, I'd just do a straight translation of the joke and then a description of how it worked in the original English.