Posted by Chuck(G) on June 08, 2003 at 18:49:05:
In Reply to: Black horn - HELP posted by Steve Dedman on June 08, 2003 at 16:12:57:
Get some warm (not hot) water and mix with a mild dishwashing detergent or hand soap.  Use a soft brush or sponge to wipe the black gunk off.  Rinse well.
Sometimes the simplest things work the best.
I've also had great luck using windshield washer solution in a spray bottle with a soft rag to clean mild tarnish away.  Some folks use Windex for the same thing.