It's not cruel. I have 4 cats, 2 declawed and 2 not. The ones without claws are the ones that were destroying walls,curtains,carpet,speakers, etc no matter what I did. The other two were trained not to do that and actually listen to me.
Recovery is quick (laser) and the only time I think its cruel is if you are going to put your cat outside. We have a screened enclosure outside that is connected to a doggie door for the cats to get fresh air, but still stay protected
