I've encountered people at bars who swear by the straw thing. Frankly, it's all in their heads. They're there to get drunk, it's gonna happen either way, and drinking from a straw won't speed it up any faster. Unless you drink fast through a straw, and savor the alcohol in a glass. Which, still doesn't make sense.
As far as water. It's a good idea to drink water if you are drunk, and also eat something.
Drinking water certainly won't make your get more drunk or have more severe hangovers. It's quite opposite actually.