I have often done the same thing with my cyberskin dildos because they are very comfy and flexible so will move with your body if you turn. I know some people are turned off just cause they have a low rating on here but I have NEVER had a problem with any of my cyberskin toys. Sometimes I just wash mine with a feminine wash (instead of the anti-baterial soap) and still - no infections or anything so they aren't as bad as people make out.

I would say silicone would be a great choice as well and then you don't have to worry about it being porous. I have also slept with my silicone Curve (by Fun Factory) but it's not as comfy while sleeping as the cyberskin is, due to the extreme curve.