I know of someone personally who used a 4000psi pressure washer with a sand injector and sand blasted a frame. He told me that he used a vinegar/water 50/50 mix brushed right on to the metal to neutralize it. The frame was then coated with POR 15. The benefit of using a pressure washer as a sand blaster would be that the water would keep the metal from building the heat normally generated with sand blasting, plus you dont have all the air borne dust/rust/silicone to deal with. To each their own, but it looks like a win, win to me.