I found that a birds nest (if you can find it) lights up pretty easy. I am unfamilar with this fire piston business.
Those pistons do look interesting. They say its a primitive tool, but I really dont see how so. I've been successful with hand and bow drills, but both are a real pain. That birch fungus is awesome and you can take it to another destination since it stays lit so long. In the pines, I've found ground-up cedar bark and pine needles make the best tinder option. These things are really fun to fool around with while camping.
It's supposed to be the prime piston tinder but I still can't get the thing to even get it warm.Al