I just thought that those wine accessories would be a handy, ever-ready way to evacuate air from bottles in the darkroom... if they do the job.

I used those compression bottles in the Gallon size. They worked fine and as far as I know repeated hot water rinses between uses kept them clean inside. One problem was that they tended to slump over (like a Slinky) making storing them on a shelf a bit ungainly. No big problem though.

How do you get the butane into the solution bottle? Do you use a tube? I assume that if you invert the refill can, it will spew liquid butane into the bottle.

Now that is just childish.
(Can't wait to try it )