I went a little overboard, I use a small cement mixer and wash mine in water and lemon juce. It cleans the pretty well and most of the time they do nt even need tumbling. If they need more shine then I use a good car polish mixed in my corn cobb media. That usually gets them nice and shinny.
I was talking to a guy about this the other day. About $150 for a small cement mixer at Harbor Freight. It will hold a bunch more brass than one of the other tumblers. He said he and a buddy can drop in 10 lbs of stainless media and the soap and water mixture and do about 1000 rounds at a time in a couple of hours. I was looking at those mixers today. It makes sense and is very tempting. I don't really need that much capacity usually but it sure would be nice to have it.