Having a "smoke" always used to make me better when I used to deejay. Perhaps it is perception, but I did listen back to what I had done after and it didn't sound that bad.
Yeah, when I was younger me and my mates used to get together and get wrecked and make music in my little studio room. Some of it was quite ridiculous - 'The Porno Song' for example - but the guitar playing was always actually quite inventive. I mean, I'm a much better 'musician' now than when I was younger, but I think there is something about being stoned/drunk that lowers your inhibitions. In some people, this means they go wild in the street, but when you are making music, insobriety can be a real boon.
Of course, its still a 'falsity' - you would be using it to lower your inhibitions, when what would be much better is if you didn't need to rely on chemicals to do that for you. I just think many parts of life, particularly as you get older, veer towards conformity and ridding one of your own 'freeness' - that's something I guess most of us would like to get back, the freedom to sing what you want, when you want, where you want without embarassing yourself, or making a mistake etc.