Parafin might be too soft all by itself. Go to, or call a local hobby shop,,people make candles,,there is a pellet type additive for parrafin that makes it harder, it's simple to add and melt with the parafin,,cheap too, couple bucks for a small bag to treat several pounds.
I forgot what the stuff is called ,I'd hafta go dig my kit out from back in the day when I was dippin candles for selling at vous' an flea-bay,,spend a little time searching "candle making" and it'll come up.
Lube the mold with some kind of vegetable oil or lanolin so the wax will "release".