“Normally, finding out a knife has a hollow handle immediately kills any interest I might otherwise have had in it.”
Hollow handle so you could make a spear out of it?
You only need a short screw or nail (screw works better and easier), and access to wood for a handle to turn these knives into very functional spears. A way to turn the screw (or pound the nail) is needed, but you can find or make a screw with a finger turned head, or carry a multi-tool or Swiss Army knife as I often do. Wire or cord can also do in a pinch; but takes more time to install and is not as sturdy, IMHO.