Strikenmike, quickdtoo is right on as far as the Flitz. But, if you don't have that, don't despair. It's not as quick, but, it does help. I didn't have any media additive a while back, when I had a thought.(and that sometimes gets me in trouble!) If you have any of the citrus based cleaners around, they help. I used some Rubbermaid grill cleaner,no amonia, and put maybe, 2 tablespoons in my tumbler, and it seemed to clean the brass better. Make sure, no matter what you use, normally you only need to add a couple tablespoons full, and make sure you don't have any brass in the tumbler when you do it. Otherwise, it clumps up like kitty litter, in the cases, and you spend time with a pick, digging out each brass. Add it, let the tumbler run for 10-15 minutes before adding the brass. gypsyman