It's not crazy, your just feeding a source of carbon for the bacteria to consume. These bacteria also consume nitrate but using vodka or other carbon sources increase there growth rate.
Personally I use sugar, for some reason I kept running out of vodka.
My 65g tank with a 20g sump worked up to taking a teaspoon of sugar to drop nitrates. Now I add a packet of sugar, just the white stuff you can get at Starbucks, or your favorite restraunt, (it's on the table by the Sweet and Low and the Equal) once a week.
My nitrates were hovering around 40ppm, now they are at zero. I was doing a 30% water change weekly. Now I do that monthly.
No ill effects IME, been about a year. I keep a variety of fish and corals. You do have to work up slowly. Dosing to much to fast will crash your tank. start with a 1/4 teaspoon, treat every other day for three doses, if nitrates don't drop, double the amount do the same proceedure. You'll get there.
I know using vodka sounds insane. But IIRC correctly a shot is about 50mL, most recommend starting with 2 mL so a single shot of vodka will last you 2 months. Not that crazy.