The answer to 'how to clean repiping' is to thoroughly flush the plumbing system after any repiping work has been completed. This helps remove any debris or contaminants that may have entered the pipes during the repiping process. The recommended steps are to turn on all faucets and run the water for several minutes, allowing the system to fully flush out.
It's also important to check for any leaks or issues once the flushing is complete, and to continue monitoring the system for any problems in the weeks and months following the repiping work. If you notice any issues, it's best to call in a professional plumber to inspect and address them.