Who's that company that makes that rust remover scrubby deally? silver/bluish color, looks like a pot scrubber. I bought one for about 7 bucks, but that thing works perfectly and doesn't harm the bluing at all! Serious.
..Big 45 Frontier metal cleaner...
http://www.big45metalcleaner.com/Works like a charm, wont scratch or hurt bluing.
dave