Bleach can be used to clean them, but different counties have different regulations. In the one county I work in, anyone can use bleach to sanitize dishes if you run out of no rinse sanitizer. In the other county, it has to be a premixed bleach for sanitizing dishes. 🤷🏻‍♀️
A descaling product would work best, but these pitchers should be replaced if they are stained. If you are worried about the waste, $1 there are a ton of resources for where to bring the plastic 👍🏻 I recommend finding a program that reuses plastic that cannot be recycled. A lot of people use plastic for projects because it takes so long to breakdown 👍🏻