A little hoppes or similar and a bronze brush and thats its,dont worry about getting it all off ,dont let it build up so much that it contacts the barrel.Years ago we had almost an entire recruit class ruin the cylinders on model 67s because someone came up with the bright idea to use a drill and stainless brush to clean the chambers and cylinder face,actually made low spots in the cylinder face,it was funny,fitting new cylinders to the guns wasnt, another story of drills and dremel tool being a guns worst enemy.Like another member said alot of guns and barrels get more wear from overcleaning than use. Good luck,