I am not sure how practical it can be made to vacuum seal glass, but the people I talked with suggested it is the best way to not have any of the scent permeate through the material. Here is a way to do it with glass ampules (https://en.wikipedia.org/wiki/Ampoule): http://www.ilpi.com/glassblowing/tutorial_ampule.html I really would rather get a formula for determining how long a normal vac bag will hold scent in though .