I have about 400 rounds of empty 44-40 brass to clean and reload. About 50 or 60 were NASTY, tarnished and somewhat corroded from repeated BP and Pyrodex loads. Tumbling it in new corn cob media didn't do a thing to it, though the treated corn cob polished the rest like new. I took the nasty brass and soaked it for about a half hour in Kaboom. Wow! It really cleaned it up. Even the ones that had some hard corrosion cleaned up with a green scratch pad after being soaked in Kaboom. I would have never believed I could save the nasty brass.