The "warm" settings on most ovens is usually somewhere between 160 to 200 degrees. (Which is, what, 70-ish to 95-ish C?) If the goal is to drive out moisture that's probably sufficient. (Just might take more time than a higher setting.) Damage to plastics aside it would seem to me that if the problem is actually water contamination the last thing you'd want to do is *boil* water that's trapped inside a glass sandwich. That sounds like a perfect recipe for cracking things. (Possibly on a microscopic scale.)