I never used one for my kids, but I DID use one with a puppy for a while! We'd had him neutered, and he was agile enough to get to his incision even with the "collar of shame" on. To keep him from pestering it, I'd pop him into a sling made with a long piece from my stash, so I could have my hands free.

We'd just gotten him, and this took care of bonding with him, and he's still excited by the sounds of the pool balls smacking on the table! (daughter and I were practicing a lot in the evenings at that time)

Karen in Boise