Mold release agent is referred to as PVA (poly vinyl alcohol). It can be brushed on but spraying gives better results. One coat, let dry then second coat, let dry. Ready to go. This is what is used even for polyester resins (gelcoat/fiberglass).
If you are using a wax (auto or furniture), make sure to apply at least two coats. Two layers of wax will release better.
