Giving permission for a Spirit to come to you isn't a question of words. Or what you say to them. It's a question of focus of intent, all on the mental/emotional levels, the unspoken.
One might think what would any dark Spirit want with little old me? Surely they have bigger fish to fry.....not necessarily so. That would be like a mouse thinking what would a mountain lion want with me? Surely it wants bigger prey?Mountain lions will eat anything they can catch