I use a mix of corn-cob and crushed walnut shells in my vibratory tumbler. I've had no complaints as this has resulted in 99.8% of all cases coming out clean and shiny. A bit of scorching or powder burn but all-in-all a good result. Primer pockets don't seem to be touched. OK, so nothing so good that a tiny bit more cleaning couldn't hurt. So I added some granular brass polishing powder to my mix. My first run of .45acp cases turned out clean, but had a matte finish instead of shiny. OK, not a big deal. But .... after looking at my results I noticed the primer pockets were seemingly a bit cleaner. This is all right! Then I started to process and load some cases. After re-sizing the cases, the matte finish turned into a VERY bright, shiny finish coming out of the carbide die. So the matte finish was temporary and a good shine PLUS primer pocket a bit cleaner makes this really neat. I think I'm gonna like this new process. Has anyone tried something like this and what result did you get?