Cut their fingers halfway off so that they're not off but the person still feels the pain. Make large gashes all over them and pour lemon juice in it. Then slice their penis clean in half deep fry it (while it's still attached) and serve it up to them on a hotdog bun and make them choke to death on it. However if they manage to survive that pouring liquid concrete down his throat should work. OR if we're not being violent I would lock them down to a chair in the room and turn the lights out. Then I would play recordings of creepy whispers every now and then until they went insane. Once that has been achieved I would let them go.