My only concerns with this method are:
- The integrity of the mason jar glass with extreme cold of butane, as well as the semi final purging glass jar & lid while being exposed to the warm water bath.
- In the beginning, when filling the jar with butane, is the use of the metal on metal lid. It scares the bejesus out of me of a possible source of spark/heat with the two metals rubbing to tighten/release the lid (whether only slight pressure is applied or not).
- The integrity of the material on the inside of the mason jar lid that's there to seal it, as well as the alloys of the lid parts themselves using butane as a solvent.
- The semi final stage of 'scraping' out the dish (that was used to purge with the loose glass lid). Looks to be a bitch of a process and why I moved to spraying directly onto an oil-slick pad.
Paranoia ? Perhaps..... but man, better safe (or as safe as you possibly can), than sorry in my book.
Just my musings and