Clean a stain on chrome?

[El Borrego]

As mentioned earlier, use the "0000" steel wool lightly.  It's amazing what it will do and then you can apply a good quality chrome polish.  I've cleaned stains and rust with steel wool.

[cookiedough]

I concur, try using 0000 steel wool with a chrome polish like the cheap turtle wax stuff I bought at walmart in a small plastic bottle for like 2 bucks.  0000 steel wool is very cheap in a small bag also bought at walmart in the paint dept.  If chrome polish doesn't work, then maybe go to soft scrub gel formula that is guaranteed not to scratch surfaces while lightly buffing with 0000 steel wool.  One last thought would be to buy a Mr. Clean magic eraser pad - believe it or not, those things work great at removing all kinds of gunk.  Just go slow at first no matter what you use and if you start seeing scratches (which you shouldn't with 0000 steel wool rubbed lightly), then stop before the scratches are too apparent.

[grover]

I agree with the 0000 steel wool AND with the razor blade idea, though both with clarification.  The razor blade should be new and perfect, so there aren't any burrs that could scratch the chrome.  The steel wool can be used with something like blue magic chrome polish to give it a little lube.  You'll probably have to buff it out with some chrome polish after either method. 

I have a pair of boots that sometimes has a sole melting problem on hot pipes.  It becomes a problem on the left side where I swipe at the kickstand.  I've had luck with a combo of razor + fine steel wool + chrome polish.