I also use rotgut vodka. I've had a couple of batches suck back (normally when carrying a better bottle by the bottom rim or picking up a full pail by the handle), and I've also pushed krauesen into the airlock. I imagine it would not have been a big deal to have used water/starsan/some other miracle magic lock-juice, but at least the alcohol in the vodka keeps the leftover krauesen from setting up in the lock.
Natural 20 Brewery
Yes, that *is* beer. Water, malt, hops, and yeast mean it's beer. Go ahead and try a glass...