Hi, Terry! Welcome to NeuroTalk!
I don't know anything about Celiac, but I can't bypass my concerns about your post.
Boy, I'd have to caution you to avoid taking advice from laypeople on something this serious. One bad tip could land you in court.
You might be better off making appointments with medical professionals and dieticians who know the specifics of Celiac and the genuine concerns in terms of cookware.
Good luck with your pursuit in this area, it could be a terrific market niche for you!