From the videos, the Zombie Tinder looks very much like a cotton ball wrapped a few times with a piece of string, then tied off and dipped in melted wax. Nice idea.

But, I can see why it comes in a tin. If it were not in a rigid package, it could get crushed and the wax coating could crack and thus leak when it was exposed to water. The tin would also contain any melted wax if the tinder was exposed to any heat high enough to melt it.

I also noted that in their videos they are using wood that is dipped into water for a few seconds. This is not the same as wood that has been soaking in water (or rain) for multiple days.

I'm not saying it is not a good product, just noting a few things that came to mind while visiting their website.