Rob - starting a separate thread for tumbling methods.
Like most, I've used corncob/walnut for ages in a vibratory tumbler. Works ok, but loud and somewhat dusty. Doesn't do much for the insides or primer pockets.
When I started shooting BPCR, I went to ceramic media in a Thumbler's Tumbler, Model B with the slightly larger motor. Wet process, and uses a teaspoon of soap. Very impressive cleaning inside and out. Downside is fooling with the wet process and drying brass afterwards. Usually need to inspect primer pockets for wedged media. Can't use the ceramic media for bottleneck cases, but there does exist smaller beads for same.
Then the stainless pins appeared. I say appeared, but different media has existed in the industrial market for a long time. The pins are tiny and will clean inside and out just like the ceramic media - but will also work fine in bottleneck cases. It's still a wet process and I use a teaspoon of the recommended soap plus a sprinkle of Lemi-shine. One to two hours, depending on how particular you are about the insides will be a gracious plenty.
Biggest downside to the pins is WEIGHT. They are heavy, and after you add the pins and water to a Thumbler's you are limited to about 70 30-06 cases per batch. These little batches annoy me. Perhaps one day I will build a tumbler or buy a cement mixer.
Different places sell the pins - here's a good place to start reading and looking. Bought my pins from them. Initial entry costs are kinda high, but unlike corncob or walnut, this stuff likely will not wear out in our lifetime.