I am with the parent who would not want the daughter to go out with a guy with such a minhag. And btw, maybe the GIRL feels the need for a drink after that date, too…
For any guy who has contemplated this minhag – spend your time better, davening that the next date will bring you the right zivug. And also spend the time thinking about what YOU might have done to make the date a better experience.
My son has gone out with several young ladies some were shayach for him and many l’chatchilah apparently were not, but he has only one time said to me that it was a bad date (the girl would not engage in any conversation at all, no matter what topic he tried to bring up or ask her about herself, just gave one-word responses, even to open-ended questions). My husband also told me that he could honestly say he never had a bad date with anyone, just that the girls were not for him or he for them, until he met me.
I know this was a topic about drinking away a bad date and perhaps it was slightly tongue in cheek, but you know what – drinking away ANYTHING is a troubling sign of a deeper potential problem, in my humble opinion.