It really depends on the level of societal collapse but zippo hand warms & fuel will always trade well. The fuel can be split & you could buy a bag of platinum embers too.
I did some quick reading, looks like it's just burning oil in a large tea kettle shaped pot. They'd point the pipe end at pagans and add water to the pot causing a directed steam powered oil fire shot. It's interesting that this never developed into a kinetic weapon.
They wash their clothes at the Laundromat but get bored and leave. Because they're niggers they return after their clothes have been sitting wet for hours and then just move them to the dryer.
I left 6 lighters in my car and they all died