I can understand the heat and clean parts of glass, but safety (don't drop it) and the extreme rigidity of glass seems to be too much. Wouldn't the ladies prefer a rigid but slightly flexable rubber toy? It would feel more real, and be able to bend slightly to your own body features. Just asking.
And yes, the slight curve could serve 2 purposes. For her, he can rub her G spot real well with it. For him, she (he, yuck) can hit the prostate.