3 questions,

Is "DIY" a chemical cleaner and what does it stand for?

How does the bead blasting work inside the header pipe? I would think the
inner corners would not be properly prepared for the ceramic coating, or is
the media inserted then vibrated? I would think the coating process would be
more of a need of a chemical clean and etch (pickling process) than a
mechanical one.

why not just buy a new tuned coated or exotic metal header for the engine,
pretty cheap compared to the money invested into the motor, imho.

Pat Thronson