One of the things that was done at my old school each Wednesday was the "Swishing" program. Each child was given a small paper cup of a blue solution that was supposed to help protect their teeth from decay. They'd swish it around in their mouths for a minute, and then spit it back into the cups...
I never did approve of the program but if the parent gave permission for the child to "swish," I had to give that child the paper cup of solution.
One parent had raised a hue and cry about it, saying the solution, while helpful in preventing tooth decay, was still a derivative of aluminum, and more harmful than good.
I agreed with her, but my opinion did not count if the parent gave permission....Sometimes I'd "forget" to do the swishing...just to be rebellious
and the kids were always glad when I would. They hated the taste, and I sympathized with them a great deal!