When Tigris was an angry young man he ruined our couch too. After that whenever we got new furniture we took care to be in the house for a day or 2 when it arrived. Whenever he started to check him out we did something like shouting at him or using the water pistol .

Next thing we bring him to the scratching post and believe it or not, he starts sharpening his claws there.

BTW I tell my husband it's his education fault that Tigris started with that couch and that Filou started to steal human food. My husband always found him too cute when he did it