Ok, lets clear some things up. Chrome is a hard metal, but it's not kryptonite. It can and will get scratches if you use anything that is harder than it is, or sharp enough to cut in to it.
DO NOT use any harsh abrasive, or you WILL scratch it up. If the rust really is just on the surface, chrome poilish on a damp cloth will go a long way. Don't grind on it, just gentle rubbing should clean it off.
If the rust has penetrated the chrome surface, then a bit of Naval jelly will go a little deeper. If it has gone this far, it will never clean up completely.
Rinse it clean when you are through, and put a coat of wax on to seal the surface...
