What the above said.
While you may frown upon using a ritual to influence someone's choices, and free will, people are doing it without even touching magic, every single day.
Every single request you make, commercial you watch, speech you give and more is an attempt to persuade, convince, control, suggest to, or influence others.
Even if you don't use people as mere means, and avoid this kind of thing, you're still doing some of it on a subconscious level.
So how unethical do you find it to alter someone's "free will"(which is already dubious to begin with) with magic?