I use the same tumblers tumbler with steel pens. About 1/2 full of water, couple of squirts of liquid dish soap, and a table spoon or two of lemon shine. Just like doing the dishes. About two hours or so, and the brass comes out like it was brand new. I have a Lyman media screen set on an old chamber pot that I dump the brass, pens, etc one and screen off the brass. The brass goes into a quick hot water bath to get the soap off and on to a bath towel where I role the brass around to get the big water droplets off. Then into a pie pan and bake at 210 degrees for 12 minutes to dry in an old electric toaster over. Let cool, and reload just like new brass. Yeah. It's kind of a pain, but I ain't never had no ammo jam nor misfire! And my ammo looks brand new......... I've been playing around with the amount of lemon shine I use and the duration of the tumble to get different cosmetic effects of the brass. Either a weathered brown or a copper color. Looks real authentic in the old time card board boxes. Why yes, I do have way too much time on my hand.................