Outers Foul Out II. You can't buy them any more but there are links to plans to build one in this thread somewhere. I've had mine for around 20 years. There are also links to purchase the chemicals to make the solution. The price is higher now but still can't be beat. I shot competition for years and cleaning lead out of the compensator on my 357 mag was impossible. The outers was the bomb! Also have issues with 9mm leading. I just let the Foul Out do the work. Every few thousand rounds in my 45's I run the Foul Out on them. Takes care of any lead buildup that may be lurking in the corners of the rifling that just doesn't come out easily with brushing.