Just a quick note about my experience with stainless media.
A friend of mine invested in a whole setup. Couple of kilos of Stainless tumbling media, a drum that is totally watertight and a set of driven rollers.
After his first go with this he raved about it so last week when I went to visit I took a bagfull of brass with me. Now, I always decap my brass before I do anything with it and you can see here one slipped through the net. The case on the right was decapped after the clean in the tumbler and you can see the massive difference between the two:
The other photograph shows the inside of the cases - these are both twice fired 308 Federal brass.
I am totally converted.