J.G.
Hi R.,
I completely understand your frustration - none of our cats are declawed. Some cats like to scratch vertically and others horizontally, so you probably want to try offering yours a vertical and horizontal scratcher. Ours all do fine with horizontal scratchers - and I like the scratching 'mats' they sell at Petco and Petsmart. They're sissal mats with a fabric edge - not the most attractive things, but they work. THey're around $10-$15. I'd lend you one of ours if you'd like to try it but it would smell like our cats which might not be ideal.
I've also used a spray called 'Feliway', which is available at Petsmart for around $25-$30 (pricey but worth it!). I've sprayed it on corners of furniture periodically, and it seems to keep the cats calm so they don't scratch. It comes in a plug-in diffuser but I think the spray works best for deterring scratching because you can spray it directly onto things (test it first - I've never had any problems with it and I've used it on fabric, carpet and leather).
Another idea is to try 'sticky paws', which is essentially wide pieces of double-sided tape that you stick onto the furniture - and kitties don't like the feel of it so they avoid scracthing there.
Believe it or not, we've managed to clip our cats' claws regularly (about every couple of weeks) which seems to help a lot. We've adopted adult cats and they weren't too keen on the idea at first, but after a few times they were alright. You might try that and see if your cat will be agreeable to it, because that would probably help. We've never used the soft paws - seems like a lot of work and kind-of expensive too.
One last idea (that I haven't tried but heard it's effective) is to bolt or otherwise attach clear plexiglass on the corner of your couch. That idea seems rather extreme to me but maybe it would be an option for your situation.
Make sure there are 'OK' places to scratch, because scratching is a natural thing for cats (as I'm sure you know). Good luck and let me know if you'd like to borrow a scratching pad, the Feliway spray, etc. :)
J.