Tumbling Brass "additives"

[gumpokc]

I ususally use a pretreated batch of either cob or walnut/pecan shells media thats been treated with jewelers rouge.

I cannot remember if I got it from Midway or if I bought it at a local gunshow, but it works great and I got 10 lbs of it for like 8 dollars back in 1996 or so, still have most of it.