Why waste time and fuel going all the way to the location of a black hole (not to mention that all the radiation near it isn't going to be good for the ship) plust the delta-V to reduce their speed until they actually are not in orbit anymore and fall down into it?
Best just jettison them out of the airlock without a suit in the middle of nowhere.
That's normal space pirate stuff. I'm taking about the extreme space pirating where people tremble at the mention of the name of the pirate because he/she/it black holes them.
Just throw them out inside a space suit without any communication devices, if you want them to suffer. Give them some time until oxygen runs out, or they die of thirst, knowing that there will be no help.