This exploded - don't do it

One of many explosions that have occurred during my experiments. This one was actually quite loud though, and the glass frit (ground glass intended as a nucleation area) literally disappeared into many areas of the room. It even blew the o-ring out of the lid. I'm glad I didn't go with a glass tube.

So perhaps methylene chloride in a partial vacuum is still the best way to make a bubble tube.

For reference, butane has a relatively low liquid pressure at room temperature. Something like 40PSI, which is why they can have plastic cased lighters.