Hello, I have no hard proof but this is what all the old timers have said for years and years. They always told me never ever use dish soap like palmolive. Use ajax or cheap brand like it. They seem to think it would make paint go crazy. Here is another trade secret. I am not supposed to say this at the office so naturally I cant wait to tell someone. FLEX ADDITIVE IS A JOKE. Most only stay flexable for 15 min or so, long enough for you to put a part back on the car after paint. Then it is gone up in the air somewhere. There are supposedly only two brands that stay flexible PPG and SIKKENS. I heard they are not great either. So be wary when painting flexible parts, Im not so sure there is a good solution.