Did I just find a new advantage of boiling?
Here is the base of my sculpture right after boiling:
As you can see it's very white! not only because of the light, but when boiling sculpey there's a film of white on top of the whole sculpture.
And here is after I've used it for a silicone mold:
The white color is removerd and never came back!, so I'm wondering if the white layer actually served the purpose of release agent for the silicone? that would be awesome! (unless the sculpey never sticks to the silicone when baked heh... don't know about that)