Electro-polishing — Works on the principle of anodic dissolution of a controlled amount of contaminated metal surface. The surface must be conducting (no paint or surface coating). Typical electrolytes are based on nitric acid, phosphoric acid and organic acid.
Ultrasonic cleaning — Used to decontaminate small metallic objects submerged in a cleaning solution. High-frequency ultrasound is converted into mechanical vibrations that scrub loose deposits from the surface. Often used with aggressive chemicals.