Our big, dominant, white dog-cat, Latte, destroyed the fabric on what once was our beautiful white sofa, quite a while ago. He has used both corners of the back as scratching posts (though we have plenty of trees and scratching toys for the cats to use, instead). We don't like this, and we always stop him, and scold him for it, but he's done the damage anyway.
He walked up to Gregg, who was sitting on the couch, and sharpened his claws on Gregg's pant leg. Gregg said, "HEY! What are you doing that for?" and Liger went immediately to the door. The next day, Liger did the same thing to Gregg's leg, and Gregg responded the same way. I started laughing. "He's doing what you told him to do - he stopped scratching on the couch, and found another way to let you know he wants to go out. And it's working!" We just trained the cat not to scratch on the couch...or did he train us?