Hello, nobodys home.
In regards to your question about declawing cats: Yes, it is true what your daughter says. Here is a diagram of the paw/claws of a cat: ( http://maxshouse.com/Declaw%20Pix/Claw-sur-dia-color.jpg ). A cat's claw, as you can see, is a direct part of the bone. They are not like human fingernails; you cannot simply dig deep enough into the flesh to "remove" them. If you only cut off the claw at the base, it will grow back, a process which would be extremely painful for your cat. In addition, the claw would probably grow back deformed; this has happened countless times with my dogs if they happen to break a claw off at the base in their romping around our backyard. In order to prevent the claw from growing back, veterinarians must remove the entire first knuckle of the paw; then there is no chance of the claw growing back and causing complications. As you can imagine, someone cutting off your fingers at the first knuckle would cause you intense pain. In addition, cats use their claws for many things, including grabbing, as well as a form of stress relief. Cats using their claws to pull on something - anything, really, as I'm sure your poor carpet knows - soothes them. Removing a cats claws puts your cat at risk of developing psychological problems such as anxiety, possible OCD, and other behavioral disorders. So, what's a cat owner to do?
Well, for one thing, an owner can provide a cat with an acceptable outlet for their scratchy ways. To further entice them to use it, you might (a) keep the cat in an area that has few other "scratchable" items and wait until the cat begins to use your post, (b) rub the cats' toys, if they have any, over the post in the hopes that you will scent the post as their own, and (c) spray the post with the irresistible force of catnip, an herb that for unknown reasons sends cats into bouts of euphoria. A cat will simply keep to its old habits if the scratching post seems unfamiliar; also, since you have multiple cats, there might be territory issues, so it's a good idea to have more than one post (probably one for each cat).
Secondly, you will want to TRY to break the cats of their already-formed habits (scratching YOUR things). Cats are much craftier and more independent than dogs; they do not inherently want to please you, and they will do what they wish if they know they can get away with it. If a cat knows that the negative response it receives from a behavior comes from YOU, the cat is intelligent enough to know that it can still get away with the behavior when you are not around. Because of this, owners must be "sneaky" in their discipline and discouragement. The water bottle tactic works IF the cat does not see you spray it. Even then, it is a gamble. Some possible other suggestions are to coat your furniture and carpet with things your cat does not like. Some examples are foil (cats hate the feel of tinfoil beneath their paws), double sided tape (cats dislike things that stick to their fur). Also, if you are very determined, you can try scents such as bitter apple sprays or even fresh orange peels, all of which act as deterrents for cats.
Finally, there is the possibility of claw MAINTENANCE. The cats can keep their claws and can still use them to relieve stress, but they will destroy nothing in the process. There are hundreds of products available to "cap" the ends of claws. You can also clip the cats' nails. In both cases, however, if you have an unruly cat that hates to have its paws touched, you either must take them to the vet or face a good old-fashioned clawing for your efforts.
There are other options you can pursue to get your cats to stop clawing. Here are three of the thousands of sites I found: I hope they fill any gaps I might have left.
I hope this answered your question!
My own knowledge of cats.