Harry Bloomfield wibbled:

The Medway Handyman expressed precisely :
We also made a paste from potassium permanganate & something else?

Glycerine!


That mix self ignites fairly quickly (10's seconds to minutes) - not a
contact explosive...

Contact bangers sound more like NI3 - but pot.mang isn't used to make this
AFAIK. Perhaps there's some extra fun to be had with pot.mang?