Recently I noticed the parts seem to be cleaned better than before. I too use dishwashing liquid (not the cheap stuff, find the one that degreases the best), then nailpolish remover on a cotton swab. I have the impression that leaving models to dry for at least a couple of days after that gives the best result. They have added a blog post by some fantastic designers about this recently: https://www.shapeways.com/blog/archives/22021-tips-n-tricks-for-painting-miniatures.html
The only "cleaning" recommended to me was to soak the the items from Shapeways in Bestine for 24 hours. This helps w/ the parts taking paint better. The soaking does work very well.
FUD does not really seem porous. I think the oil evaporates. They produce FUD items with some sort of wax as support material. They then melt away the wax in a low temperature oven. After that they dunk the items in some sort of oil to disolve the remainder of the wax. Strong&Flexible plastic is porous, but there's no problem with painting that, other than paint bleeding through very thin parts.
I've just bought this new stuff it comes in a 32 Fl. oz. plastic bottle Non-Toxic, Biodegradable and earth friendly. it's called KRUD KUTTER cut grease, grime, oil, tar and wax. Caution: eye and Skin Irritant. I just started using it and it seem to work I use it on a few piece from broken models. I soak some small pieces in a plastic cup for about three mins. took them out and ran water over the parts! them dried them and painted them the paint seem to go on smooth no oily spots and looks good. but these where small pieces. I used the stuff right out of the bottle no added water so it was concentrated. I had a depressed center flat car also 3D printed it hasn't been painted yet but I have had it for a while there was built up wax on the bottom between the car frames. I took a stiff brush and put some of the concentrated cleaner all over the bottom and just brushed it and let it set for a few mins. then ran warm water over it and let dry it didn't turn white like the Bestine does to the plastic but still see thru but there seems to be no wax or oil between the frames. this 32 fl. oz bottle cost about $6.00 and some change without taxes. I bought it at Home Depot and also saw it at Wall Marks. I had left a few pieces in the concentrated cleaner about 10 mins. and it still seems flexible and very bendable so it seems not to dry out the plastic. now Only time will tell. It will also remove dried paint!! Best southernnscale
Hmmm. I've written myself a note to stop at Home Depot this week. If I can get some for around $6.00, that quantity, well worth trying.
