rr 2030 did you read my post?
I would try tossing them in the H.F. black wet with acetone see if you get results , H.F. red is the easiest to use I have used all four colors of H.F. paint some need longer baking time than others .
As my notes say I have never tried the "shake and bake" method I would see if cheap spray enamel is available in your area and give it a try