But then you have to train a cat to buy more matches at the store for the mouse and they always try to eat the money.

Excellent idea

If you are using household concentrations you won’t generate enough chlorine gas to be harmful in a ventilated area, like outside. If you put it in a bag and huff it you are going to have a bad time, but enough to cause damage can be tossed into a mason jar, shaken, and thrown pretty safely.

The acid makes it rust in seconds instead of days though, instantly visible and quite permanent damage.

Well, a 1:1 mixture of chlorine bleach and vinegar should damn near instantly and permanently corrode the steel. Don’t breathe the fumes, but I have toyed with the idea of a squirt gun filled with instarust.