Learned something new today about the citric acid process. I had sectioned a case so I could look for a possible defect in the inside because of a bulge. I had the bright idea to wash it in the citric acid. I attached a paper clip to the case so I could just hang it in the solution for a few minutes and expected to be bright and clean. Went back in about 10 minutes and found the case was black. The citric acid had removed the zinc plating from the paper clip and deposited it on the brass case. So....... don't submerge metal parts of a different material in with your brass cases for cleaning.