release agent for hydrocal/plaster of paris

hey to all,

I'm looking for tips on a release agent to use on some molds I've built for the sides of a model farmhouse. I used to have this type of  info on hand in my model train building days but for the life of me I can't remember what to use. The molds are built of wood. I'm thinking wax paper or maybe vasoline or a grease of some sort? I know I wouldn't have a problem if the molds were made out of rubber but they're not. Any help on this would be appreciated. Thanks in advance for any suggestions.

Hud