Several years ago I heard about a product that was used to internally sleeve or line, leaking water lines. The description of it made it sound like a plastic, rubber, or vinyl tube was run through a section of copper tubing to repair “slab leaks”. There was one type for cold water lines, and another one for hot water lines. Is there such a product, and who makes, or supplies it? If it is available, it could potentially save us a great deal of money.