:hehe: There is alwayz a risk that the air tube can become clogged. Matter of fact there is risk involved in everything. That doesn't matter though as I use gatorade bottle that bend and are very flexible and the glue on the bottle cap would probably go before the bottle would explode. I would never use a glass bottle!
I once left one of the valves to one of the bottle closed for 2 days and nothing happened. So I'm not too worried.