Re: release agent for bedding?
Many things that leave a non binding film will work for rifles.
For potting magnetics in epoxy before putting them in outer space, high vac grease. Not high vac for space, high vac for the vacuum chamber used to get the bubbles out of the wet epoxy.
I use a combination of foam rubber, masking tape, and Redding Imperial sizing wax to prepare a rifle for bedding.