I've done that too - the "handle" was something on the order of a tongue depressor, one on each side the blade and then wrapped with electrical tape or whipped with nylon cord for a better grip. The ones in the attachment kind of take that to the next level (and then some).Great videos...! ! !
Reminds me of my father making short knife blades from hacksaw blades. He would make a slot in a dowel shaped piece of wood, then put the blade in, then jam it into a piece of conduit for a handle. He would sharpen it to cut leather for shoe soles. Blade wouldn't be any longer than an inch...sometimes straight, sometimes curved. He had a few made for various cuts.
The good ole days, eh...?