Furniture is just a depreciating material possession. Love is priceless.....

Have you tried those scratch-guard things? It's like some kind of clear plastic you can apply to the corners of your furniture. Cats find the texture unpleasant and unrewarding to scratch. Just an idea

Our cat does the same and I've noticed it's more about getting our attention than actually sharpening his claws. He knows it'll illicit a response out of us every time.

Those are the parts of the room that need their smell subtly corrected. Also, they feel nice.