The spellcasting scene in the grotto

I know a lot of actresses (and actors) will take on a bit of "Dutch Courage" prior to doing a nude scene, i.e. doing some imbibing before the scene.
Here we have the four newcomers doing a protracted nude scene. There's a jug of "sacramental wine" the characters brought as part of the ceremony and the actresses are doing a lot of drinking from it.
What I'm wondering is, might the jug really have been full of real alcohol? Watch the scene again. Those girls are either getting tipsy or doing a dang fine job of simulating it.
Not that I'm complaining! As a Clea DuVal fan I get a kick out of watching her drunk and naked and still doing her lines.