So for the past year I stopped using tumbler or my new sonic cleaner and have simply used some 00 steel wool and my hands to clean the neck and 2/3rd's way down to the head. I hated the fine powder or film I got in the tumbler from the walnut/corn. I was worried the inside of the necks were better off not being cleaned so much in the sonic cleaner and hated worrying if they were completely dry afterword. So, tell my why this is a bad thing. PS I usually only load 20-50 rounds at a time, and would never do this I shot much more. I do wish I could find a good chuck to use so I could spin them in a drill or something.