I've fics where Nolan!Joker is described as smelling variously of peppermint, gasoline, sweat, old sweat, BO, unwashed hair, leather, tobacco, gun oil and greasepaint. This is the first time I've heard of good ol' sweat, piss and shit.

Personally I think he looks like he might smell a little sweaty when he's in full-on smudged greaspaint, just-been-beaten-up-by-Batsy mode, but he doesn't look particularly unwashed at other times. His clothes are pretty neat and tidy. I'll vote for gasoline and greasepaint myself.