http://www.sharpshootr.com/ Used this stuff called WIPEOUT over a year now, just put my bore guide in. Shake up the can squirt down the boreguide till it comes out the muzzle. Set for a hour, I leave it overnight. Best part here you don't have to brush, it also has a rust inhibitor in the foam so you dont need to run an oil patch. Push your dry patch through in the morning and a whole bunch of blue liquid comes out. I usually repeat this a second time, it gets all the copper out.