Rushtucky, good for you! I looked the stuff up on the internet. It looks like it is a very mild abrasive so your caution about multiple rinsing is very good indeed. The ad says it restores to pistons to "like new". That of course is a lie. Restoration would have to put material BACK onto the valve instead of grinding off more. It worked for you and thanks for the tip and the report. Keep the valves properly oiled and the wear will be minimal.