You generally don’t want to. In current it can pull the doors shut, and it’s likely to get tangled in boat props.
But it can pull double duty as float and something to hook when you’re not dropping them off structure. Provided the line doesn’t sink when water logged. Which paracord won’t. Also it doesn’t rot.
My brother improvises fishing bobbers from it.
ETA: the right way to do this is to tie a monkeys fist in a short section of floaty paracord with a loop or two in it. Then connect that to line that will sink properly. The fist can be tied around a chunk of pool noodle, which is cheap and won’t rot like cork.
The lazy way is to rig your box traps with paracord you don’t know will float, and just roll with it.
