Personally i think it's a load of bollocks, pretty sure there's not a single proven scrap of actual real factual evidence for any ever working, but hey you can say the same for about 4000 different Deities and that doesn't stop millions beleiving in, and killing for.

Plus they can be good fun, as teens a few of us made one when we satyed in a hotel during a school trip & set up a routine that scared the younger kids shitless. then a teacher bought it off us and we used the money to bribe the teacher's assistant to buy us booze. So I've had nothing but good experiences with them!

Sounds like you guys got the demon Witchboard 1986, seem to recall that sneaky spirit pretented to be a friendly kid n tricked a young couple....