You are glossing over details that make you seem uninformed or lazy.

Also, this is not a feature in hard drive firmware. A scrub like you are describing is a feature in filesystems or raid solutions. A disk on it’s own will not rewrite data over itself. Show me a product page from a disk manufacturer that says it does. If you can find it, it will not have been a popular drive because of the increased power usage and reduced life of the drive.