Brasso works, but Wright's Brass Polish works twice as fast for me. Available (at least here in Mass) at the grocery store. I use it on stepper rivets too. I like that it's non abrasive, and makes them shine like gold! After cleaning off the white residue, I use the teflon super lube as others have mentioned. I smear it on with my fingers for a nice thin coating.
Wrights also works great on solid state contacts, particularly pop bumper switches and leaf switches. I used to use the business card method, but found it didn't work very well for me. Just remember to wipe the white haze off with a clean rag once it dries.