Definitely. I'm toying with the idea now, perhaps for my Dereg sheath. It's not too bad, but the stock sheath rattles a bit with the knife in place. Gotta figure out how to secure it inside the sheath though, I'd rather not glue it.
I suppose I could install a grommet into the sheath and run a screw through a retention hole like on the above design, but that would limit the direction of carry, I would think... Hrm.... decisions decisions!