Moon water is a historical tool for witches. It has been used since at least the 1800s for love spells, and is even more popular today. Its connection to emotions and spirituality makes it an incredibly versatile tool for witches everywhere.
Moon magick is one form of magick that brings most witches together. While not everyone works with the moon, most witches do moon magick at some point in their lives. Even simply making moon water to use as a spell ingredient is a form of moon magick!