Best way to sanitize all the plumbing in a new rv?

I believe the recommended amount of Clorox to use is 1/4 cup for every 15 gallons. If you don't like Clorox you could use Trichlor, the stuff they use for spas. It is much stronger than Clorox so you only need a tea spoon or 2. You might as well sanitize your hoses while you are at it.

I do it every spring.