maybe try Castrol Super Clean.
That and Chaos' suggestion are both good.
You could also try oven cleaner spray (NOT the fume-free kind, which is a lie anyhow: it has noxious fumes, too!
). Easy-Off will literally strip the paint off of a battleship's hull. I'm not kidding, because I've seen it done
(Yes, of course, I tried to suck it off through a garden hose because I just enjoy sucking so much -- no homo, naturally.)
Eh, where's that strike-through feature when I need it. Ah! There it is. I just painted myself into a corner and can't think of a good way to use it for that parenthetical comment :|
But jokes aside, Easy-Off will pretty much clean anything.