I think it's just that he's an alcoholic, so some said... then they add some baloney excuse like it's good for drying out or whatever. That alcohol had anything to do with Ronnie's form is obviously complete baloney lol, but people enjoy these types of shitty stories...
Dorian had a glass of wine the night before a show
It has a relaxing effect and is a mild diuretic
Why do you think you have a headache in the morning after a few drinks?
Its because you are dehydrated