Word for the flavor of Listerine mouthwash

Solution 1:

Perhaps not a word in the dictionary, but it is used often to describe Listerine: mediciney.

Marketers at Procter & Gamble knew that their formulation killed germs just like Listerine did. But Scope’s secret ingredient wasn’t its cetylpyridinium chloride or domiphen bromide. It was a marketing term—“mediciney”—that hit Listerine where it hurt. 

From http://www.adweek.com/news/advertising-branding/perspective-big-kiss-146411

Solution 2:

I would pick FF's astringent (Oxford):

2.1(of taste or smell) sharp or bitter.