Is it something used in the embalming and preparation of corpses?
Ewwww!
No. It’s used in conjunction with something you probably encounter every day of your life.
Just so you think I’m not a total lunatic–I had remembered that you had said that after you used it, you had to get another one. (Of course, I slightly misremembered that.) And I just re-read Jessica Mitford’s The American Way of Death, which discusses the preparation of corpses in great detail. So, I figured it might be something to retain some body part or something, and you couldn’t reuse it because it would be buried with the corpse. Or something like that.
Okay, so maybe I’m a total lunatic. It made sense at the time.
I don’t think you’re a total lunatic. 
Okay, a wild guess:
Does a garden hose go between the prongs of the forked end and the swivel bit used to constrict the flow?
If not, does something shaped like a garden hose (a rope, perhaps) go between the prongs of the forked end?
No and no. However, something does go in between the forks.
Will you tell us what industry it is used in?
There appear to be two tabs on the swivelling bit – one upturned and one downturned.
The downturned tab appears to restrict the swivelling bit from turning the full 360 degrees. Does it have a purpose apart from that? In fact, would the thing work if the swivelling bit could turn 360 degrees?
Does the upturned tab serve a purpose? Would the device still work if you broke it off?
Spaghetti eating fork?
Does it pull knots tight on a curtain draw cord?
The downturned tab does serve a purpose. The upturned tab serves the purpose of not allowing the swiveling part to go 360 degrees. The device could work without it, though.
Does it have something to do with a telephone cord?
Duke of RatCrafter_Man - Not cords, but it does tighten something and you do have to twirl it.
:smack:
Left out a comma there. Didn’t mean to fuse you two together.
No cords of any kind are involved, though.
Like a car? If so, does it have something to do with seatbelts?
I’ll throw out some wild guesses. Does it have anything to do with food preparation or sailboats or cable tv or piano tuning? Or any combination thereof?
Does it tighten (or untwist) the wire around newspaper bundles?
Damn this thing looks familiar.
Is it some sort of special-purpose adjustable wrench? You slide the prongs over something, then adjust the arm so that its tab hooks on something else and then the whole assembly can be rotated?
My guess… screwdriver or, eh, nail driver for the lack of a better word. Kinda like a proto-cordless drill… sometimes you just don’t have enough wrist strength.
It doesn’t do anything, that’s the beuaty of it.