Sorry, but you’re about 30 years late with this idea. See the link about Cynthia “Plaster-Caster” aka the world’s most famous groupie. 
http://www.nardwuar.com/cynthia/
Love stinks! (Yeah, yeah!)
Well dang, I wonder what she wants for the whole shebang.
Why isn’t she making more money off from this ?
More than you ever needed to know about the molding process.
I would just like to know who would be working in your quality control department (aka the Q-tip brand anal thermometers post)?!
“Quoth the Raven, ‘Nevermore.’”
E A Poe
Plaster of paris gets hot as it cures and can burn if too much is used. Alginate is better for body casting.
http://www.barnesproducts.com.au/Pages/Alginates.html
Are you sure you have the right fluff?
My Jesus fish can beat up your Dawrin fish but forgives it instead.
Get some wet sand, stick the turgid member in to it & press for a great fit. De-turgid the member by thinking about PI to 245 place,pull it out, then pour in the plaster into zee hole.