Originally Posted by 
Would it work with cotton balls soaked in petroleum jelly? That would be a good available fuel in current society, and a good stable fuel you could pack into 20oz soda bottles to store for ATSHTF, and it would lube the o-ring to keep it from wearing out too quick.
Might want to try. Remember - this is essentially the principle of diesel engines, and they ignite kerosene, so it might work. On the other hand, it might take a lot more compression to get the heat concentrated enough to light vaseline. Also, the vaseline will burn, where the charcloth will smolder. The difference is how much and how fast the oxygen in the chamber gets used up - and thus whether you'd be able to get the burning cotton ball out before it smothered due to lack of oxygen.