its an incindiary, based on evolved gas.

calcium carbide can be used instead of Mg Hydride, to similar ends.

https://rexarc.com/blog/calcium-carbide-for-acetylene-produc...

A guest on Joe Rogan was touting non-nuclear hydrogen bombs just last week. Maybe that's why they're out of stock. He didn't mention how dangerous they are, that's irresponsible.

https://www.amazon.com/Unosuich-Hydrogen-Bathing-Molecule-Ge...