I use dryer sheets and swear by them. It must be a used dryer sheet and I just lightly brush it over the object to be painted, right before I spray it. It has always worked for me and I used to always get particles in my paint, rarely do anymore.
I often wonder why Shapeways can't provide a simple key word search function. The other annoying thing is that you can search by scale but the picklist doesn't include 1:24 or 1:25.