Closest thing I can think of to mouthwash flavored booze is Rumple Minze peppermint schnapps.
I remember back in my college days you'd buy you and a girl a shot of peppermint schnapps before trying to hook up, so your mouths both tasted fresh and minty. Either that or Aftershock for that cinnamon flavor.
Then again, I'm weird in that I'm totally cool with the "Colgate kiss." Some people don't like too much toothpaste taste in a partner's kiss, but I can digs it. Better than a stale Dorito kiss, that's for sure.
That shit is terrible haha. I remember when I was a kid schnapps was all over the place. I can't remember seeing it in a liquor store .... but then I'm not looking for it either.
In my early-late teens there was a dual attack of schnapps. Aftershock, cinnamon flavor, and Avalanche, mint flavor. Those were my first real sick drunk.