In my experience most of the products out there are not necessary, it's great for business obviously it's selling and the manufacturer are making money but are those really necessary/needed for the well being of your animal?
I can tell you that if a Ball Python is healthy, eating and well hydrated he has everything he needs. I have raised a few snakesand never provided any of them with any type of diet supplement nor do I intend to do so.
Now if there is an health issue with the animal it's different but than I would expect that whatever is given to the animal is recommended/and or prescribed by a herp vet.