Well. The thing is that not only that entity can come, but others can as well (not always good things) and their energy can be a lot to deal with also, particularly when we are new to this life. There’s a lot of ways to banish, and the LBRP and it’s various versions are often recommended, however I don’t care for it myself.
I personally push out my own energy to push out anything unwanted- mostly lingering energy from summoning and a ritual from Ben Woodcroft’s Angelic protection magic, as it’s much simpler to me than the LBRP and easier to remember on the whim, like if I scared for no reason. I also use servitors for banishing and warding my space. I banish entirely for the lingering energy from entities and protection from unwanted things, not from the entities that I summon.
One of the servitors I made publicly available to the forum, and she essentially does everything for you, you just need to summon her. She’s able to either stay with you for constant protection and to ensure that only the entity you want to connect with comes, or she can be sent away after banishing and warding your space. It’s personal preference, users here do both.
If you let her linger, she won’t banish anything you summon that is what you summoned or their lingering energy unless you ask her to. She won’t banish familiars/ubis and things of the like either. I think it’s important to still know how to banish, as you never know when you might unwittingly attract a parasite or malignant entity or in my case get attacked by another witch, but she’s great for use in conjunction with your other practices, on the whim and until you learn what works for you.