I wouldn't want to find out.
I don't think it's actually directly poisonous the byproducts after it goes through the liver is what's bad for you excluding the fact that it's acidic, so it might not trigger a general 'don't imbide this' reaction from most people, at least it shouldn't be any harder to drink than straight grain alcohol.
That's one of the reasons it's so bad for pets, it smells sweet and tastey and it doesn't trigger an involuntary gag reaction or anything. Used to be very common in Anti-freeze and sometimes windshield washer fluid, used less now because of the danger to household pets that don't know any better.
Ever heard of a Sterno drinker? People used to actually intentionally drink the stuff. Destroys the stomach because the acidity and the liver byproducts build up to toxic levels fairly fast if any significant amount is had. It does however result in a 'high'