That's something that hardcore alcoholics believe. You can absolutely smell and taste it. You can smell it on their breath, and coming out of their pores the next day. In fact vodka breath is just about the most distinguishing liquor in that regard. I remember PT tests in the army and you could count them as you ran past them. Other drinkers, it was much harder, maybe they're struggling cause they're sick? But vodka hits you like the brick wall of Aunt Miriam's perfume.