Once your interruption stops the clawing, direct them to the legal target and praise them when they do the right thing. Yet another option for hard-case kitties is vinyl nail covers like Soft Paws. These claw covers glue over the top of each nail, and come in a variety of fashion colors. They are available from pet supply stores and some veterinary offices. You can learn to apply them yourself.
Every cat is different.
What works for one may not work for another. For instance, Seren thinks the squirt gun is a fun game. She wants to be squirted. And when claw behavior is prompted primarily by stress, you ll need to address those issues as well. Stress Relief Cats adore status quo.