I recall reading somewhere on here about someone cleaning their tumbler media periodically by putting it into a sock and running it in the washing machine. After running about 6000+ brass pistol cases through my tumbler (of which I had added some case polish in some earlier loads), my corn cob media was looking pretty black and starting to take a bit longer to clean the brass. I put it into a sock, and threw it in the washing machine, hot water, added standard clothes detergent, and let it rip (while my better half was out of the house). If I had remembered, I'd have done the double rinse, but I forgot. That corn cob media cleaned up NICE!! Like brand new. I did run a second load on the washer (empty) to clean it out afterwards I opted NOT to bake it in the oven at 200 for now to get out all the moisture. Instead, I've spread it out and will let it air dry (turning it once in awhile) Anyway, just thought someone else might benefit from the info. And my thanks to the person who originally posted the idea in another thread - I can't seem to find it right now.