I'm curious about whether two things I experienced are related, maybe if I share it with a larger pool of people others might have noticed something too!

One of them is a side effect of medicated mouthwash, active ingretients cetylpyridium or chlorhexidine. The former belongs to the quarternary ammonium class of antiseptics, while the latter is grouped with them due to the identical mode of action.
I could go on a long angry disgression over the disregard of phase 4 clinical trials (the studying of rare or long term effects of already approved drugs) and the fact that Crest is under no obligation to add the freaky side effects of their Pro-Health product line into their official documentation, but this single sentence says what needs to be said so it shall be a short rant.
So, thanks to this oversight, there's no information on how frequent this side effect it, but if you google "cetylpyridium taste" you'll get many freaked out posts on various health forums from people who lost their sense of taste after using the product. It happened to me. Thanks to the previous users' panicked posts, I learned that this was usually temporary, the effect numbs chemoceptors on contact but doesn't destroy them. Also people who keep using it develop a tolerance.

The second thing is when a friend offered me a bag of salmiak. Which I didn't like much. It tasted of licorice, but kinda weakly, and was rather bland otherwise. I'd eat a little, but saw that the rest of the bag would eventually dry out and be wasted, so I handed it out to coworkers and relatives.
And they expressed surprise at discovering salty candy, which isn't usual in Canada. I tried another piece, but couldn't detect a hint of salt no matter how I tried. The others swore that salt was the dominant flavour, nothing subtle at all.
Now, salmiak is made with ammonium chloride, not sodium chloride. Salt taste receptors detect the chloride ion, not the cation. Any highly soluble chloride salt is supposed to taste salty. Since I can taste regular table salt, I know my salt taste receptors are functional. So, are they inhibited by a high concentration of ammonium ions?

And that's where I'm going with this:

Would immediate taste inhibition by ammonium (if that it what is at play at all) and lasting taste inhibition by quarternary ammonium antiseptics happen to the same individuals? If anybody else on the forum had that mouthwash side effect at any point, I suggest to try salmiak candy and see if it tastes like it should. And post it obviously. That's no rigorous research, obviously, but for curiosity's sake!