So you have tried other means to stop a bad habit or bad behavior from your feline, and it has not worked. Cats do not act out of spite, so it is up to you to find a way for them to express their natural instincts in other ways. Cats scratching your furniture is a natural marking behavior in the wild.
Of course, domestic cats do not have trees to mark, so they scratch on furniture instead. Place a scratching pad, or a scratching post next to the piece of furniture they are scratching on so they can mark that instead. Try both, because one may work better than the other. You may also try double-sided tape. This deters cats too.
Also, relieve boredom by leaving several toys, or a box of shredded up newspaper for them to play in. You should also enrich their environment. Give them a cat tree to hang out in and play on. Also, you can give them a window perch so they can look outside and see what is going on. Hang a bird feeder outside the window to really spice things
If your cat is getting onto places you do not want them, place foil on the surface. Cats will not walk on foil. They do not like to walk on spiky surfaces either. Use a plastic doormat on any surface you do not want your cat on. You can cut the doormat to fit to size. Most pet stores have ready made items like this. The double-sided tape will work here too.
Leave the television or radio on for them too. The sound will give them different sights and sounds. You can think of other ways to occupy your cat’s mind, so they do not get into mischief. Take away the temptations too.
Don’t leave food on the counters or table, keep the bathroom door closed, or any other door closed where you do not want your cats to be. Keep the litter box clean as well.
If these do not help with a bad behavior, a water bottle or squirt gun does really well. You need to witness the attempted behavior, then squirt them BEFORE they do the behavior. Watch them and you can tell when they are just about to jump on the table, or scratch your furniture, or use the potted plant as a litter box. Spray them in the rump, NOT the face.
By squirting them with water, they do not associate this with you at all. You are detached from the stream of water. Even if you give a NO command at the same time you squirt them, they still will not fear you, and they will learn that the No command really means NO!