I received my Stainless Steel tumbling set up yesterday and I was so impressed with the first load of brass that I decided to see what this stuff will really do. I pulled about 40 pieces of brass that I had tossed into the recycle bin and tumbled them for about 4 hours (changed water after 2 hours). I added 1 teaspoon of Lemi Shine and a squirt of Ajax to the water. The water was hot from the tap.