[Proleps]

Punishment also works on cats. You just have to be very consistent when applying it (this is exactly the same for dogs). If you punish your cat(or dog) you have to do it immediately. If the cat is done scratching its nails, and you squirt water, you are too late.

[Edit] Changed negative reinforcement to punishment, rbehrends was correct when he pointed out that negative reinforcement is something different.