http://www.ncbi.nlm.nih.gov/pubmed/21604830
I think that this illustrates that you do not understand that completely.
There are even suggestions of long term benefits. The authors concluded that for middle-aged subjects, increasing levels of alcohol consumption were associated with better function regarding some aspects of cognition. http://aje.oxfordjournals.org/content/160/3/240.long
PS: Initially reflex tests where considered for in car breathalyzers, but many people performed better slightly over the legal limit than they did normally.
I've experienced this once before, not with coding but with software testing. Liquid lunch (couple of pints of Guinness), and was a lot easier to focus on work after lunch because the slight buzz kept me feeling warm and happy, I remember being quite productive. It's not something that I'd want to make into a habit but I definitely think it can help with focus on repetitive tasks (so long as it's well within your personal limits).