Chastity gadgets produced using 3D printing

Those bespoke chastity gadgets appear to be manufactured via 3D printing. Are there any engineers among us who can weigh in on the advantages and disadvantages of creating a custom, measured device? Also, what about the filaments for these printers—can they utilize materials that are safe for skin contact? Lastly, if the answer is affirmative to either point, does anyone have a template ready to share?

I believe there's already a discussion on this exact topic here. It probably includes links to some examples... but you'll need to do a bit of digging since I can't quite recall the precise location.