Depending on the type of of rubber the tube is made of some bicycle inner-tubes dry up with exposure to the elements (latex type I think). Otherwise, if you use the right type and it has pressure on both sides it will act as any other rubber seal, so I don't see how it will trap moisture any worse. I use bits of them between the latches and feet on my roof top bike rack on my daily driver a little more than three seasons out of the year with no issues.
They're not solvent resistant but I don't know why you'd be getting too much gas on em.
