AH senior member
Just been cleaning up some more brass in my new rotary tumbler. I wish I had changed to this system before now. 1 hour in stainless steel pins, hot water, a squirt of washing up liquid and half a teaspoon of citric acid and hey presto beautiful shiny clean brass inside and out. It's cheaper than the normal vibrating tumbler with walnut/corn media, faster and the results are 10 times better.