I do not now how long it takes to be oxidized into unreliability.

But, my mindset is this...

My kit will get wet.
My kit will be mangled
The contents of my kit will be wet.
The contents of my kit will be mangled.
Thus, the items in my kit, must, in every instance possible, be reasonably durable and reasonably water-resistant.

Trioxane does not meet these requirements. So, I do not carry it.

Also, I feel that proper knowledge and technigue of fire-starting is really the key, with what understanding I have, which is shallow compared to the guys with real dirt-time, I am able to get a fire going with a metal match and fatwood in nearly any circumstances. Of course, once you have the fire started, the need for an axe can become quite acute.