Blast on the surface the use on cannon fuse seems as it would be a good fire starter. And you might get it to work.
But the ends where you would light it it is not water proof. The end where it is to do it's job needs to be sealed. Then it is either lit out of the water or is sealrd to an igniter.
As it burns it self seals and where it does break through the expanding gas keeos the water out until the burn advances beyond the rupture.
Most of the burn is internal to the coating that keeps it waterproof. You get occasional spurts of flame along the length but not that much. Also the fuse needs to lead to something flamable to ignite.
Any tinder that would be sensitive enough to be reliably lit by the fuse. Would also be as easily lit by wht ever method you would lit the fuse to begin with.
The mentioned fire starter is in fact a self lighting enhanced form of thermite. The Potassium permanganate when exposed to the Glycerin is the self igniter portion of the formula. The called for aluminum is a bit coarse. You really need about 400 mesh for good thermite with the other half the iron oxide about as fine. The addition of the Magnesium is what gives the enhancement out a hotter burn. It is an arson special.
That compound will generat enough heat to start a completely soaked log. The Glycerin and Potassium permanganate is all you need for a good starter with even minimal quality tinder. And Potassium permanganate can also be used to purify water, used as a disinfectent and in strong mixes as an antifungal treatment.
http://en.wikipedia.org/wiki/Potassium_permanganatehttp://www.travelhealthzone.com/away/water/5-purification.phphttp://rk19-bielefeld-mitte.de/survival/FM/06.htm