22cal might be an issue but not 6mm or bigger I’ve been running groats since I read the thread on CGs.....
I tried Groats for a few months and it gets stuck in anything with a case diameter under 27 cal. I shouldn't have to shine a light into every case to verify the media is out but I do with Groats. It pretty well sucks when you've loaded 400 rounds and start getting compressed loads because you randomly have five grains of Groats in your 6.5CM brass. Nevermind that it clogs up small primer pockets despite internet users claiming otherwise.
I've gone backwards on all tumbling; wet tumbling for pistol and bulk milspec 556/308 only and fine ground corncob for match rifle brass. Berry's sells corncob by the five gallon bucket pretty cheap, just throw it away after a while if the dust is a problem.