“Napalm” is usually considered as a weapon. What you meant is probably just “emergency firestarter”, or as I would call it, turbo-tinder :D
I personally prefer using cotton pads, that are soaked in liquid candle wax. When it’s cold, it hardens and the whole pad gets stiff and hydrophobic.
Instead of having to lift a glass jar, you can just slip a few of those discs into your pocket or a small bag.
And because the wax is hard, you don’t have to worry about storage, and they will stay that way forever. With your polystyrene goo, you have to remember that the jar will never be 100% gas tight and it will evalorate over time.
The pads even work when wet (because they won’t get wet) and can be used with a ferrocerium rod.
Also, styrofoam releases toxic gases when ignited, wax won’t.
The key thing is to only slightly coat them. If you smear too much on them, they won’t ignite that easily.
But yeah. The wax should be very runny and hot, so it gets soaked up by the pad. And then heat it, so it re-melts, for example with a very hot heating gun or baking oven.
And when you want to use it, just tear the cotton apart a bit, so the fibers get exposed, and it will ignite instantly.
I like it more than petrol jelly, because it’s hardened and not as sticky.