All of my jars are vacuum sealed, without having to do anything special. Just put the tobacco in it and wait. The magic bugs eat up the oxygen pretty quick and set the seal on their own. When I go to open them, I hear the swish of air.
Same. Every time I pop open a jar, even one of my "not necessarily aging" blends, they pop from sealing themselves. I think some folks put a bit too much energy in to worrying about it, but hey.. It's their foliage.