I finally got around to trying pin tumbling, it's not quite as good as I'd hoped, but I'm willing to mess with it for a little longer. I'm using a Thumbler's Tumbler that was given to me like 10-15 years ago, that I think I gave away at some point, and then was given back to me, we used to use it for deburring machine parts with little ceramic stones, but that was a long time ago. I think there's still some goo in there from the old uses but over-all the brass did come out a bit more yellow than the golden hue it had before. a little more burnished, and both the pockets and the inside of the cases were quite clean. When I dumped out the tumbler an angry mix of blue/black soup came out.
As far as chemicals, I started with Lemishine (citric acid) and Dawn dish soap. I used 1/2 tbsp of Lemishine and about the same of the Dawn. I opened it up around the 2 hour mark and it seemed like it needed more soap the cases were sort of greasy feeling, so rather than using more dawn, this time I used laundry soap, after another two hours I pulled it all apart, dumped the contents into a sieve to separate out the liquid and washed it in my garage sink thoroughly. I think poured the brass and media back into fresh water, and then picked the cases out of the media/water by hand just to be sure to separate everything. It felt like there was still a little goo on the cases, so if I'm going to do it again, more soap. I might do a tumble with corncob and some media additive to put some wax back on the surface, or maybe I'll try some liquid application waxes. I dunno, just something to keep the brass from oxidizing.
Anyway, if y'all got some tips or pointers, chime in. I've been thinking about getting one of those FA tumblers, they're supposed to do 1000 5.56 at a time. I'm kinda in a weird spot as I do really big loads of 5.56, but really small loads of other calibers.
I have a bunch of really ugly .38 and .357 I'm going to clean up this way next, and then maybe some .30-30.