sisvicki,
Thanks!
You wouldn't happen to be a yooper, would you?
(I just happen to be a peninsulanian myself. L.P.)

Pennywise,
If I may answer your question to Vlad. I hope I'm not stepping on any toes...

With silicone, you usually don't need any release. But hey, it won't hurt.
With paper-mache and silicone, I don't foresee any difficulties. Except possibly some distortion caused by pressing the mache in too hard, just pay attention to the mold and you'll have no problems.
Silicone (100% that is!) won't stick to much, and vise-versa.
But as always, do a small test to see if you are about to waste your efforts and money!
Especially when using materials for "non-standard" purposes.