Clobetasol
"It's a foam which I like, and it dries fast and clean.  It's a pretty strong steroid so it does work, but obviously you can't stay on it forever.  Within a week or two of using it, it will clear up your patches, but again as soon as you stop using it they will come back.  I've got pretty good insurance, and it still cost me around $100 for a bottle.  I recommend it for the really bad tricky spots, but don't use for too long as it will scar your skin."