Yes I tumble once fired range brass,in walnut media ,this cleans out carbon in cases , then I anneal them,then they can sit and don't draw moisture,carbon from the powder burn if left will draw moisture and start turning the brass green, if left over time it will pit the brass surface and act like rust on steel ,and ruining the brass pieces . After your walnut media has cleaned thousands and thousands of brass pieces ,I use small screen from windows it's made from a tough plastic,but flys can and do chew holes in it lol, I'll double it up then pour my media on it and roll it back n forth, what falls through is very small pieces of media and dust of carbon ,which I sweep up and throw away ,ps, the dust is very fine so I wear a covd mask .cheers