Spray primer update....... Tested on 20033 giant rats. (Very bendy plastic.) Left rats on sprue and scrubbed minis well using old toothbrush, warm soapy water as per suggestions in this thread. Original test using rustolium 2x black primer stating on can that works with plastic. Rustolium still tacky after an hour and rubs off farly easily. Second test on second sprue using Figure Painter black primer spray. Dried fast with no tackiness, also sprayed directly over tacky rustolium and worked just as well as original test, drying fast and took the sticky feel away. Figure Painter also passed the flexing test with no flaking, chipping or rubbing off.