Thought I'd get some opinions on cleaning used brass. Here's my method.
I remove the spent primers first with a universal non sizing de-primer tool then load the shells into an old 10lbs rock tumbler with stainless pins, dish soap, a little bit of LemiShine, and water.
Start the tumbler and let it do it's thing for at least 4-5 hours; sometimes all day.
After they're done I drain everything into a separator and then rinse the shells and let them air dry.
The stainless pins do a much better job of cleaning than any dry medium I ever tried and even the primer pockets look good.
So far this has worked perfectly on modern or black powder residue with once fired brass, range collected stuff, even my all brass shotgun shells.
Ride Safe. Dr.Tramp...........