I know it..
We used to make this Ammonium Iodide compound.
Its perfectly stable when wet as in a paste, but the stuff is so unstable when dried out that a fly landing on it will set it off.
They taught us how to make it in high school
You put a dab of that under the toilet seat lid LoL
Or we’d put it on the inside of a kitchen cabinet door and leave it open. Some one would slap the door closed and “bang” it would fly back open!
The only time I thought my momma wanted to kill me was when I left some potassium chlorate and sulphur mixture on the garage floor. It frayed the heel on her shoe and she damned near killed me, LOL. I have never seen a woman lose her cool like that again! Drug me up the steps by my feet, so I could tell she wasn’t really hurt! Momma could hit a rattlesnake from 30 feet out with a lawn edger, it wasn’t a good idea to mess with her.