To the original poster though, I’ve been in the business of evocation a long time. Provided you’re banishing before and after the ritual your not in danger of possession. They have to want it too and there’s an element of your consent involved.
Don’t worry about going to hell either. You’re not selling your soul ( they don’t care about that kind of thing really, that’s just hollywood)
Here’s a good guide on evocation made simple. I use this all the time