I use crushed walnut in several tumblers...small/large vibratory and a rotary Thumlers.
I find the walnut flows out of bottleneck brass much easier. YMMV, but I always end up with chunks of corn cob in the case and can't get it out.
Like mtbkr, I prefer function versus shine. On the other hand, if you're not in a rush, the Thumlers puts a shine on brass like I've never seen. Of course, I usually leave brass in there for a very extended amount of time (ie, 3-10 days).
Dryer sheets definitely works.
I live in a fairly rural town, so there are feed stores in the area. They have crushed walnut in 50 lb bags for just over $10. I have no less than 5 in my garage at any time. Reloader friends and family always seem to grab one or two when the come over.
Ed