I ran a test of using the Hornady cleaning solution in my wet tumbler (using no pins) against dry cleaning using walnut media and some Nu Finish in my vibratory cleaner. Both ran for 6+ hours. Wet tumbled on the left and dry cleaned on the right. While the slightly tarnished shell on the left is most likely more authentic, I think I am going to stick to the dry method. I want it to be as easy as possible for the brass pickers to see my shells.