Did this when we were kids, with kerosene.
Lots of fun, but at least a couple of the people I knew who were doing it a lot just seemed wasted all the time.
We were (usually) rinsing our mouths out afterwards, and sometimes drinking milk beforehand to give a better lining to the mouth etc, but in the end, it’s not good for you, toxic shit, blah blah blah.

Oh well.