[samatman]

I think that carbonation actually helps, yes.

It has a positive affect on an irritated stomach lining, I've found. This is easy for me to explain when it's slime/phlegm doing it, as the bubbles helping enzymes and stomach acid dissolve the goo.

I'm seldom enough drunk to have a good sample, but liquor isn't good for the stomach, and I've cautiously drunk a pint of sparkling water with complete success, while knowing that still water would have come back up within five minutes.

Maybe the stimulation of the bubbles promotes the lining to exude what it's supposed to, which alcohol strips away? No idea but I do think it materially helps.