The methanol will boil off at 64.7 °C and the ethanol will at 78.4 °C. I not really sure exactly how they do it, but I think they just wait until they hit the ethanol temp to start collecting it. They probably collect the from 64 C up to 78 C and throw it away. I would definitely not drink it if you didn't' know exactly what you were doing. It wouldn't be fun to live the rest of your life blind...or maybe dead.
Oh and don't take my word on the temps either I found it on wikipedia.