For really tarnished brass (range pickups) I soak them in a solution of 1 cup, vinegar, 1 cup water, 1 tsp salt, 1 tsp regular dishwashing detergent for 15-30 mins (shake every 2 or 3 mins). Then I rinse them very good and throw them in wet into walnut (medium size) with a cap of NUfinish car...