It's only trial and error until you find their "pressure points"/Yellow and Green options. Then it becomes the same thing every time. Since there are only 4 core responses, that's not very "trial and error"-y, to me anyway.
What really throws the commusystem for demons is that sometimes they'll ask for gold and a "yes" response will piss them off. There's nothing you can do about that in that case since it seems the mood of the demon can change on a dime there compared to the 4 canned responses.
If I remember right: There's lower encounter item(s) you can use to break the Random Encounters down, but for the most part: No. It's an old-school RPG, so you have to stomach the encounters.
In the end the secret is befriend just a demon for dungeon (or just when you want), because free card grind are the optimal way to get new Persona. Even I would turn crazy to try every demon contact.