Have you tried teaching him to use a scratchig post?? Sometimes, if you try a few different materials, you will find one your cat really loves. Of my three cats, my male cat Cinder only uses scratching posts (unlike the girls) and I never see him scrathing at furniture or anything else. We got him as a young kitten and taught him to use the scratchers and he just took to them. His favorite is one with seasel rope and carpet around it. One of my females uses the seasel a lot as well, but from time to time she scratches the top of my sofa where she hangs out, so I think it is a territorial thing. The water gun works fine for that. She only doies it occasionally. My other female, who I adopted as an adult, loves to scratch at one of those cheapy carboard scratching posts. But she also loves to scratch at window frames. But I'd never declaw. I have declawed past cats, one because my parents insisted and two because my ex-husband insisted. None of my current cats are or ever will be declawed however. I have put my foot down! And luckily, my new hubby agrees!! You should be very proud of yourself for convincing your parents.