If you were nearer I'd suggest come and steal the one my daughter insisted in buying. Despite playing with other things (that he shouldn't) the NF studiously ignores it!
Jasper didn't use it ever, not even when it was new so I donated it to a friend at work and her foal takes it everywhere with him!
Depends on the horse I suppose
I picked a Snack Ball for my horse as at least it had the allure of treats inside to keep it entertaining (for horse and observers)! I've never used a Jolly Ball, but knowing my horse he'd ignore it after a few bops around.
I bought a jolly ball & it laid unloved in the field for about 10 years, ignored by various horses. Then I got a rescue Rottie who found it & absolutely loved it. It survived about 18 months of rough daily play, & I've recently had to buy him another one. The handle gets shaken off fairly quickly, but he trundles it about playing football with it, & unlike a football, it 'squishes' so he can pick it up.
So, yeah. I wouldn't spend £20 on one for a horse unless you have a Rottie ready to pounce.