So it turns out that SWIM's plaster dry mix lists the ingredients (he hadn't noticed before
). It contains calcium sulfate hemihydrate, calcium carbonate, and crystalline silica. He knows the CS and the silica will word just fine for rendering anhydrous acetone; he's not positive about the calcium carbonate, but considering that most bases seem to pose no problem, he's not worried. He's not positive about how any of this will work with alcohols, but he's quite certain it will work well for that as well. He's rendering some anhydrous (400F in the oven for and hour or so, not seeming to drastically change consistency, but this should work as low as 302F) at the moment and will try it out quite soon.