it is true that alcohol disinhibits you, what happens to me is that the more anxious I get, the more I stutter. This used to be a huge problem when I was a teenager so when I went out I tried to drink to be able to speak "properly", but with time that need disappeared. What has worked for me was to start talking as much as I can, I used to avoid talking to people like cashiers or when ordering food on the phone, but once you expose yourself to this stressful situations, other situations start feeling less stressful I guess. If you want to drink alcohol at a party every now and then as long as your using it responsibly go ahead, but don't just get drunk so you can speak more fluently because even like that it won't go away