Clip them with special clippers. My cats get excited when I take the clippers cause they know it means treats. It doesn’t hurt them, but they get stressed if they feel forced.
Don’t let your cats hunt, it devastates wildlife. They will absolutely just hunt for fun, with more energy even if they’re well fed inside. Don’t get a cat if you can’t keep it entertained. Get a bunny.
It wouldn’t work as an indicator if it actually hurt them, is what I’m saying. Clipping and medication etc is only a problem because it can be stressful, and you can take all that stress away with a little conditioning.