Reminds me of that guy who started drinking water upside down to train his swallow muscles and cure his chronic heartburn.
There's some science on training those muscles, even without upside down drinking. "Dry swallowing" while on an incline seems to do the trick just fine.
https://pmc.ncbi.nlm.nih.gov/articles/PMC9550520/
In Japan, I learned to drink water upside down to stop hiccups. Works for me, whereas drinking normally doesn't.
Did it work?
There's some science on training those muscles, even without upside down drinking. "Dry swallowing" while on an incline seems to do the trick just fine.
https://pmc.ncbi.nlm.nih.gov/articles/PMC9550520/