Playing drunk CAN make one play better. I say 'can' because it does happen, but is rarer than many want to believe. Of course, most drunks have to be drunk to even operate on an even keel. Then there is the rare person, such as a guy I know, whose brain constantly gets in the way of his game. Being drunk eliminates that problem.
A little story.... The guy I mentioned, was a low B player at best. He got in a ring game in a bar with his brother (an A player), myself (A player), another A player, and a couple of strong B's. He had nothing else to do, and knew all of us, so, we were happy to let him play. He gets absolutely snockered. He is so drunk that he can't even sit in a chair. Everytime we sat him in a chair, he would literally pour out of it like he was made of water. We then would laugh, and leave him on the floor until his turn. When it was his turn, we would pick him up and bring him to the table.
I'll be darned if he didn't play some of the best pool I have ever seen! He ran out from everywhere, racks at a time! We were all dumbfounded. He was so wasted, he didn't even know he was winning or know enough to collect the money. We did shove the money in his pocket after each game. He ended up winning a little over 200 and we were only playing for a dollar a man! Next day when he woke up, he had no idea where all that money came from, but he sure was happy to have it!
So, it CAN happen, but far more often than not, a player will go broke once he gets drunk.