On another thread, Elizabeth brought up a very good question which no one answered.
It is my understanding that for an exorcism to be successful, the exorcist must have the permission of the local bishop. According to many books about this subject that I have read and tapes I have listened to, it is important to the resident demon(s) as well, as they mock and taunt a priest if he doesn't have this permission. This would make sense, since what got satan into his mess is his "non serviam."
Has anyone here ever heard of an SSPX or sedevacantist priest that successfully performed an exorcism without the permission of the official bishop of the diocese that they have their chapel in?