Thirded
I assume 3M makes those inserts for their hooks because it’s difficult to mass-produce cheap hollow objects with a firm flat back.
We don’t have that problem.
I have stuck all manner of things to the wall with command strips — power strips, 3D-printed hooks, boxes.. whatever has a flat back works fine.
It’s funny but for non-dog people: this is actually measuring something. If your dog is so upset that cheese is not interesting then that is a very upset dog.