Aprolium is NOT a pesticide. Its a Thiamine Antagonist.I think the way you are feeding them is fine but just a quick note - the medicated feed does contain pesticides (C14H19N4+ · Cl−, e.g., amprolium hydrochloride).
If you were looking to feed an all natural feed without chemicals, I would not feed medicated feed. Not saying what you are doing is wrong whatsoever in the slightest, just sharing feedback regarding the chemical. I'm a advocate for amprolium when used to treat coccidiosis, but I choose to not give it when it isn't necessary (sort of like giving antibiotics when not necessary - my school of thought is there has to be a level of resistance that is established when certain things are a constant). The chemical is also known to have side-effects associated with weight gain in poultry - which can be a good thing depending on how you look at it.
For treats, you can raise your own mealworms inexpensively or maggots if you have a compost pile - that way you know what is going into the treats.
Yes, its a chemical. As is everything else. But it is NOT a pesticide.
and the side effect "weight gain" is the result of lesser competition for nutrition from the coccidia present in their gutt.