Force treachery was a force power only ever learnt by the most evil super overlord in galatic history, Darth Elmo . It takes several hours for Force trachery to be put into effect, meaning you must do it secretly without your enemy knowing, Darth Elmo successfully did this.
Force treachery comes from the hands of its user. It look like a shiny point object....a knife, which stabbed the treacherous person in the genital area, killing them very slowly. Once this was done, the knife would hang the body from the roof.