Hairspray will work as a release agent, as it's PVA (polyvinyl alcohol), which is what most release agents are.
You're probably better off buying some real release agent and spraying it with an airbrush, though you can apply it with an old t-shirt. You want it to build up a film.
When I bedded actions, I used plain old paste wax. You can tape over any holes (like, say, the ones in the sides of 10/22 actions and trigger groups) before you start, so the epoxy wont flow in.
If you decide to use something like West Systems, you can add something like cabosil/fumed silica to thicken it. You should try sanding this stuff once the epoxy kicks- it's like sanding a rock. The long hairs in cabosil is the same stuff in asbestos, but it it really makes epoxy incredibly strong.
If your epoxy comes out gummy, you probably got the mix ratio a little wrong. Follow the manufacturers directions- does it need a 4-to-1 by volume mix, a 25% by weight, etc? A cheap digital scale is always a good idea. Mixing cups are cheap at your local composites store- I use Tap Plastics, but you probably have something similar where you live.
You can gouge out gummy epoxy and clean the area with solvent, or Goof Off, and try again. I've definitely been there.