Problem Finding begat Problem Solving!
It troubled me that students would plop the glue gun on the counter top in between squirts, leaking glue and causing a burn/fire hazard. After searching for a wall-mounted solution, I ended up making my own design in @Tinkercad and printing on one of our @Ultimaker printers.
After several incarnations (and a small pile of plastic), I settled on a relatively simple model that will hold a mini glue gun against the wall during use or while cooling. I posted my design to @Thingiverse here: https://www.thingiverse.com/thing:5377878