Brownell's Accra Release is the cat's meow on release agents due to the ease of application and removal.
All the paste waxes are great, but more labor intensive.
The only gun that I have ever stuck was with Pam.
There is a trick to bedding a rifle and not having it stick with what ever you use.
First Degrease your action with brake cleaner, twice. Degrease the stock screws also. If you are using a plastic stock, degreaase the inside of the stock area to be bedded and drill 1/8" holes in the stock to act as anchors for the
bedding compound.
I spray two coats of the Brownell's Accra Release on the action and screws after degreasing.
When the action is removed from the stock, use the brake cleaner to easily wash off the Accra Release from the action and screws.