I am in Philadelphia today to do a seminar on the Principles of the Family-Based Maudsley Treatment. In preparation, I've been talking a lot to people about how to present these ideas without causing quite as much resistance. In many ways, we're talking about "One More Bite" of a medicine that isn't welcomed by people who often don't see a use for taking.
My toolbox for persuasion on this has mostly been "evidence." But that doesn't always work well. I've been trying to get past my frustration with that, and found Apples don't fall far from the tree very helpful.
I haven't worked out how to be more effective, or if it is possible, but this trip to talk primarily with therapists is a good chance to try.