Thought I would pass this on for general info. I just bought a batch of plated 9mm bullets that were a little cruddy, tarnished and dirty, thought I would try some lemi shine (powdered citric acid) used to clean dishwashers) I have a rotary tumbler and also a vibratory tumbler so I tried it in both. I mixed about 2 -3 tablespoons of Lemi shine in about a quart of water, The ones in the rotary looked brand spanking new in 10 minutes or less, the ones in the vibratory took a little longer and were duller. I did find that in the rotary unit I had to let the mixture gas off before putting the lid on or the drum would swell up. It's pretty economical cause one quart (3 tablespoons) has done about 3500 bullets so far.