Let the balls soak then wipe them clean. Nail-polish remover is another way to go, if you can stand the smell (working outside helps). If you don't mind the clanking, you could even put the golf ...

One GOLF.com staffer claims ... bucket of warm soapy water. Let the balls soak then wipe them clean. Nail-polish remover is another way to go, if you can stand the smell (working outside helps).