lacquer thinner. > my preferred cleaner. Dries fast, cleans well, no residue.
goofoff or goobegone works great. >Must be some foreign substance...
rubbing alcohol. >same as isopropyl 70 % Works OK, but slow and needs some time to let water dry.
acetone >also works great, leaves no residue, dries very fast...
ethanol >why waste good booze? Leaves some sugar residue as well.
Alcohol, cue-tips, >slow, leaves water residue, and cue tips can leave lint. (I prefer old, well washed nappies...)
arcticlean set > hard to get, and too costly.
razor blade > slow, and leaves behind some old paste.
Brake Cleaner > was great, but I think that the formula has been changed for some greenies...
mineral spirit > slow, leaves behind an oily residue.
alcohol based hand sanitizer gel > Might as well use something like wet ones... Too much residue left behind.
OR JACK HAMMER > THAT'LL WORK!