I've learned if your subject has lots of detail and inaccessible surfaces, you're better off going with WSF Polished or Frosted Detail. Best home solution is called 'elbow grease.' I've had good results with a spray can of Gunze Sanyo primer followed by sanding, etc. etc. till I get it where I want it. If you insist that it be perfect, get a set of putty blates/knives or whatever they're called. Of course, you risk losing the smaller detail. The good news is that the material can take some rough handling.