A rubber chicken.
The quarry which I used to patronize a lot has several wrecked cars down deep, and one of them is a Ford Falcon station wagon. Some wag tied a five-inch-long rubber chicken to it in years past, but the chicken got lost/buried in silt, so I decided to replace it with a bigger one that wouldn't get lost.
Accordingly, I went online and ordered a good-sized rubber chicken, about fourteen inches long. She was a handsome beastie.
I then took my rubber chicken to the quarry and, on a surface interval, commenced to rigging the chicken for her final dive. There were no good tie-off points, so I decided to run cave line through the manufacturing hole in the chicken's belly, run the line up through the chicken's mouth, tie the line into a loop, and then cut off enough line to tie the entire assembly onto the Falcon's buoy line.
Stuffing a whole bunch of cave line up into the manufacturing hole was pretty easy...but getting the loose end to drop through the chicken's mouth? Not so much. Cave line is lightweight and floppy, and that chicken had a narrow throat.
I fished around with a screwdriver for about ten minutes, getting nowhere, before I decided to ask the dive shack staff if they had any long, pointy tools that I could use. They didn't, but the cute teenage girl working the desk said, "I have small girl fingers. Let me try," and sure enough, she stuck her finger down the chicken's throat, poked around for a bit, and came up with the string.
So anyway, that's how I got a teenage girl to choke my chicken.