I had this exact same discovery when I started going on nights out regularly from 18. When I went to university I also went through a phase of taking mdma and cocaine on nights out, which also improved my stutter massively! Fortunately I was very aware that drinking or taking drugs regularly just isn't an option if you want any kind of normal life. The only thing that did nearly get me was when, again at uni, I discovered valium, and how easy it was to get hold of at the time. Popping a few valium throughout the day would keep me in such a relaxed state that my stutter improved massively. Unfortunately a side effect of that was I don't remember a good 3 months of my life, and you build a tolerance anyway so the effect on my stutter quickly diminished. Just remember the negative effects of becoming dependant on drink and/or drugs will massively outweigh anything you gain from stuttering less. It is much much better to come to the realisation that your stutter doesn't need to drag you down. The reason drink/drugs do improve it is because of the confidence they give you. If you work on improving that yourself then it should be possible to obtain the same results without them. And even if you can't achieve that, people care about your stutter less than you think. They'd care about you being an alcoholic or junky much more.