No, not really.
Dichotomous is usually a technical term, and wouldn't be used to describe a family situation. To describe your brother in such a black-and-white way would probably be taken to be very rude.
You make something acceptable. You don't institutionalise something acceptable. The statement is also untrue!
Making someone conform to your beliefs IS brainwashing them. They happen at the same time, not one after the other.