If that's all it is, any good aluminum polish like Mother's.
Before you rub your fingers to nubs, though, clean and polish one area on the rotor side thoroughly. If there are pits, stick a fork in them, they're done.
If they are really bad. Go to your local northern tools, harbor freight tools etc or truck stop and get the wenol metal poilsh system. worked great for me!
I used to use Wenol, but several months ago I found this stuff called Boms Away and I have been extremely pleased. It works on all metals, including chrome, and it's non-abrasive so it will not scratch. http://www.bikecleaner.com/id4.htm
I used to use Wenol, but several months ago I found this stuff called Boms Away and I have been extremely pleased. It works on all metals, including chrome, and it's non-abrasive so it will not scratch. http://www.bikecleaner.com/id4.htm