H2O vs. 0 cal. liquids?

I too am told that anything 0 calorie and caffeine free should count. But here is something else to cosider. A weigh****chers leader said this during a meeting, and it really got me drinking water more.... If you were to clean out your kitchen sponge, would you do it with caffeine free coke? lemonade, crystal light, a bottle of propel? Probably not, right? The water is used for your bodily functions, the purer the liquid source the better for your body. Just food for thought. Donna