Agreed. I used to use it in their water and saw little to no difference. In fact, they slowed down in laying and drank less water. As soon as I stopped, laying went back up to normal and they started drinking normally again. Maybe coincidence, but....?
I think someone made a list of all the brand of feed people on here use... was it @Kiki ?
Also depending on where you live there may be local feed mill that makes chicken feed from locally grown ingredients. That's how I get mine. It would be somewhat the same as what you want to do but they'll...