Feliway is a synthetic analogue of the feline facial pheromone — sounds confusing, but it is really quite simple. Have you seen cats rubbing their cheeks on an object? What they are doing is depositing some of this facial pheromone on the object and marking it as theirs. This feline facial pheromone can also be thought of as a feel good pheromone. Meaning cats sense this pheromone and it has a calming effect.
Cats are territorial by nature, and like to delineate their territorial boundaries. Scratching is one of the ways cat mark their territory. Not only does scratching provide a visual marking of the territory (the shredded material) but also, cats have scent glands on the bottom of their paw pads which deposit a scent discernible only by other cats.
Spraying Feliway on objects you do not want your cat to scratch effectively depositis this feel good pheromone so your cat doesn’t feel the need to scratch the object.
You will still need to provide a scratching post so there is a place for your cat to scratch.
For more information on Feliway, you can visit their website.