Tumbler, vibratory, plastic barrel with washing soda and battery charger, molasses, braided wire brush, muriatic acid, and for high volume in a hurry a five gallon can with mesh bottom and pressure sand blaster. Tend to mostly use what will clean while we are doing other work. On alloy parts we use an ultrasonic bath or a vapor degreaser. Probably others with a home shop do it differently but we can't charge a customer shop hours for doing one bolt at a time.
