My horse is one who loves to grab his halter and launch it down the barn aisle, steal his neighbor's bell boots and launch those, drag his blanket into the stall with him, etc, so I bought him a Jolly Ball thinking that he would love it. He showed absolutely no interest. I tried shoving little pebbles into the hole so that it would make a shaking noise when he hit it, and there was still no interest. Put it on the ground thinking that maybe he'd kick it around. Nothing. This was all still happening while he was throwing his halter and anything else down the barn aisle, so I tried hanging the ball on the outside of his stall thinking that maybe he'd play with it if it seemed like some sort of deviant behavior. The ball wasn't touched, but I'd still find the halter on the ground! I finally ended up taking it down and giving it to a friend's horse, who loves it.
Despite my disappointing experience, I know several people whose horses love them. It isn't a lot of money to spend, but I'd still ask around and see if a friend has one you can use before going out and buying one that your horses may ignore. I ended up putting a hanging salt lick in my boy's stall and he loves to knock that around. Go figure!