TTI Header “ break in “ thoughts

Hi all , I have a new set of TTI ceramic coated headers ( big Block Dart ) I’m trying to not mess up the coating on initial fire up so I’m going to run them on a test stand with a used motor to get them “ broken in / heat cycled “ what can you offer for guidance as far as how long do I have to let this motor run? Should I run it for five minutes shut it off let them cool down or just let it run for 20 minutes half an hour. Please share your thoughts with me on this.