My cat did that. Once I was sitting on my computer chair and she thought my innocent twirling was cause for a game, and leapt upon my bare legs and dragged her whole weight down them. THE PAIN WAS RIDICULOUS.
She grew out of it though, once I'd had her spayed and started letting her outside. I wouldn't declaw a cat, my cat gets in lots of fights and she'd probably be killed if she didn't have some line of defence.
I would use the water spraying,although to be honest, I just avoided her when she was in a clawy mood!