>>/799/
Making a serious attack against them usually convinces them to fuck off. Aiming for the metaphysical 'heart' -- that is, the nucleus of meaning that the being is based upon -- can seriously harm or even kill many entities. Remember that a lot of them, especially the predator types, rely on fear rather than actual power in order to control people. If you break this illusion they become mostly powerless.
Simply assuming a dominant highly aggressive mental stance can also work. Make sure you don't get tricked into becoming a loosh cow though.