I have never washed any miniature to get rid of mold release. I think there have been a couple in my whole history of painting minis that I would say have had problems painting due to that. I think I have one satin primer that I used that repels acrylic paints, and gloss paints definitely will. Prime with flat paints and in my experience you won’t have enough problems to make it worth washing and drying every miniature you ever paint.