I was thinking it was a joke.....cause there's clearly product on tho9se pegs Just no price tag....? haha.
Dollar Tree has them for a Dollar
But, my father told us as kids, the blue tablets are actually "bad" for the rubber within the tank....they tend to gum up and cause deposits that will stop the flapper from sealing properly....
So we typically just use the little hanger fragrances that hang inside the toilet bowl, and when you flush, water runs paste them, cleaning the toilet basically