There can be weak spirit meddlers who are so fearful of the light they choose to leave rather than risk capture, which they believe will be fatal. In most cases, the dark spirits will not budge whatsoever because they view it as an idle threat. They have heard it many times before. They have possessed human beings again and again who pray to God, who pray to Jesus and nothing happens, and that is because the person lacks high enough level faith in themselves or in the divine to bring an effective force to bear and remove these intruders.
In the meantime, these are just words, they are not actions. It is akin to ordering a burglar to leave the premises. Some may do so because they are afraid of a greater force that may eventually be brought to bear, but if they are tough and you are unarmed in any other respect, they may well stand up to your threatening words and then what will you do? If you are in a state of high belief, both in the divine and in yourself, you can ask for the divine to remove such spirits and this will be done at your request, but if you are dealing with an imposter misdirecting a channeler it will almost certainly be the mind of a physical extraterrestrial psychic who is present on the earth as a physical being and is not afraid of God, Jesus, or any other divine being. They are atheists. They understand all of our religions and the pantheon of religious figures we think of and refer to in discussing spirituality and in our personal beliefs, as in mounting prayers, but they believe in no such powers and will not be intimidated at all by such threats.
After all, again it is just words. If you command something be done in the name of a divine figure, it is you using your power. You are not explicitly requesting the divine to come and do the removals. That is a different matter altogether and it becomes a delicate business because this represents a contest of free wills. Both a channeler and the extraterrestrial imposter have free will, so there must be a fairly sophisticated awareness and understanding of what one is dealing with and direct entreaties to the divine realm to block the access to the mind of the channeler to prevent an interaction and help the channeler build sufficient defenses to avoid falling into such a trap. This is very difficult for channelers to do on their own because they lack the motivation, they become very enamored of their channeled source who they presume is divine, and never question it, or if they do, will not want to cause offense or demonstrate a lack of faith in introducing such a challenge.
A clever imposter can deal with most presumed tests of faith and have no qualms about doing it because they lack a conscience and do not believe in divine retribution or interference to begin with. So to them, invoking God or Jesus Christ is not a threat at all and they will be able to deflect any such test quite handily. Your elegant solution we have discussed with you elsewhere is the very best way to expose a deceptive consciousness, but exhorting any intrusive consciousness to leave is a very weak strategy and will often end in failure. This is a major reason that exorcisms fail. They assume more power on the part of a priest who is borrowing partially the trappings of the divine, but not getting the divine realm directly to come to the rescue as they presume is happening.