Interesting modification. I have a "survival" knife that was given to me many years ago that comes with a gizmo that fits into a slot in the blade to turn it into a similar type spear/harpoon.

My problem with the idea is this: even with it tied to me with something stout, e.g. paracord, do I really want to risk what is a key part of my equipment being dragged off into the bush, to be lost forever?

About the only realistic scenario I could come up with is spearing fish, so that the fish doesn't slip off after spearing. And for that purpose, I think a sharp stick and the wire might me just as effective. Don't want my knife going to the bottom of the lake/river/ocean either.

Still, ideas like this are something to keep in mind and in our bag of ticks.