Hello. Good morning
If it works as the shacles in chain decoración. It should work with unconveeted thralls. ( Drag an unconvious thrall and click on the decoration with it on the rope
The option is just a suggestion , that could work. Since it wont take a deployed thralls ( as you know we got limit as to how many thralls we can have in the world. And this is a non functional decoration.
Currently you use those nemedian decoration by moving your own deployed thrall in the same way as you would do when sitting thralls in chairs. .