Glacial acetic acid is the consistency of honey and smells terrible. Where did they even get enough to do that in the first place? Even a chemistry lab probably wouldn’t have enough to do the job.
Any fertilizer will kill plants if you use enough of it. For a small area, like cracks in a sidewalk, Epsom salts are perfectly OK.
It apparently has food, drilling, and photography applications. This HS was in one of the wealthier neighborhoods so money wasn’t going to be problem and one of the kids dads may have owned a company that used it
I’m just trying to kill off the fragile young shoots of annual weeds that show up immediately after the rain. My yard is basically just dirt and there aren’t many ornamental plants near by. I’m going to try it the next time it rains, or at least maybe regular strength vinegar and Dawn and see what happens. My garden is raised beds and won’t be near where I’m trying to keep the weeds down.
That leaves the problem of fertilizer runoff, which is bad enough from lawn fertilization without adding to it in a misguided attempt to kill weeds.
I encountered it in chemistry lab in college, and HS chemistry students probably used it as well. We had to decant it under a fume hood because it was so unpleasant to work with.