Try cleaning them first with automotive paint polishing compound (not wax). This will take all of the oxidation off. They'll look like chrome. Then follow that with denatured alcohol to remove any residue from the polish. Denatured alcohol can be found at any hardware store in the solvent section.
In a message dated 7/2/2009 4:11:04 P.M. Eastern Daylight Time, tspit74@comcast.net writes:
Also, concerning the manual, it lists 2 solvents I've never heard of for cleaning the heads. I've also heard of using denatured alcohol. What's the best thing to clean them with? So far, I've rubbed them clean with a dry, clean, cotton tube sock.