I usually take a qt measuring cup and fill with HOT WATER straight fro the tap, and add a Cascade or FINISH dishwasher capsule, and drop all of it in after the capsule dissolves and you mix it up. Let soak for 15-20 minutes, Rinse in HOT WATER and use a small brush to get the grains of the detergent that hasn't dissolved, out of the grooves. The wash water will be a dark brown from the nicotine, and breakdown of the dyes of the knobs (no UV protection). Then polish with Mothers Mag polish and a Dremel. The crud is washed off but the brass parts still need polishing.