found some you tube videos by fakefood5656 he's sculpting and some 1/6 scale anime models
videos are in japanese, but at least there's plastic boobies
Shows him vaccum casting at the end of this video
http://youtu.be/hQwjlIWCL1o
and continues on this video
http://youtu.be/tk1RtUVV7AY
He's obviously using split molds but the idea of wrapping them in wax paper to create the resevoir never occured to me, will definately give it a try as it's genius.