He does a pre bath using ultra-sound and a pressurized bath. He microblasts the entire injector including electrical contacts. Also he considers the four spray ports superior to the stock injectors with pintel jets. I had a long convo with him about not just injectors, but fuel saving vaporizer systems for throttle body injectors which I have been thinking about for cars. He doesn't want old injectors to clean; instead he is focused on selling improved injectors with up to 12 spray holes.