I've used the double sided sticky tape to good effect. Also I got a HUGE scratching post for them. They like to be able to stretch up to use it. I sprayed a bit of catnip on to make them like it more 😂
Also maybe try some other toys. Sometimes cats scratch out of boredom
I have a post and I never witness my cat scratching furniture (although I know he does as it’s pulled to bits) and he uses it every day. The other thing I’ve been suggested it’s double sided tape all down the sofa but that looks awful! I tend to hide the arms of my sofa with a throw so he can’t get to the bit he likes to scratch.
A really big, fat sturdy scratching post stopped ours. Something tall enough for them to have a proper stretch on, that won’t wobble when they give it a good scrat. Any furniture scratching we have now is very light touch, and is attention seeking rather than serious
The trick is to give them something they prefer. Downstairs a coir door mat worked well (just put it on the floor near to the area that was being scratched) & upstairs a wicker chair (which has been wrecked a bit but it was v cheap so easy to replace). The chair is very stable if they want to have a full body stretch! Also covered the armchair downstairs they were scratching with a blanket & they didn't like that as much.
I think it is a matter of consistent training. If I saw my cat scratching the sofa, he would be immediately removed and taken to his scratch mat. In the early days of training, I would use a water pistol, so that he associated that negative behaviour with a negative outcome. When he used his scratch mat, he received positive attention.
It's very difficult to keep my cat out of my bedroom as if I close the door she normally cries outside all night and wakes me up. But last night I closed the door and I didn't hear her all night. Maybe I just slept very soundly. I'll do it again tonight to see how it goes