I have those same bones for my dogs. What I do is plug one side of the bone with peanutbutter. Then I place the bone in a bowl with the peanutbutter side on the bottom.(the bone is standing so the plugged side is down and the open end is up) then I fill it with chicken or beef broth(it wont leak because the peanutbutter blocks it) and freeze it. Wait a coaple of hours and serve. my dogs love them.