I think in JH mind he thought he created real "Napalm" because he loved the diabolical aspect of being a mad scientist.
What he was creating was more like just a sticky flammable substances.
Alhtough he did create a good substitute for napalm.
Like using Sterno cans which are like a sticky gel that is flammable that you use when camping to heat up food. You see these also at buffet style restarants to keep food hot under the food.
I am not sure what real napalm has in it but he was close with his mocking of it.
I think real napalm is petroleum jelly substance with flammable liquid mixed in.
The idea is it shoots out of flame thrower and then sticks to surfaces while igniting.