I always joke that if I had a dime for every time I told DS4 "Use your words," I could hire someone just to tell him to use his words!
Sad, but probably just about right! I said it MANY times a day for many years! The scale thing worked much better for us. (Naturally YMMV...)
I guess I just think that if they knew how to use their words, they would, you know? The scale gives them another, very different way to think about the whole thing. That's why it worked for DS4, I think.
Plus it's numbers, and numbers always appeal to him lately...