Man, silver/silver chloride is the coating, not the plastic body, so printing the cup doesn't really solve the skin contact question, you still need the AgCl layer for it to work right. What resin are you using though, because most aren't meant to sit on skin for hours?

Man, this reminds me of a used copy of a hiking guide I bought online that had someone's notes all over the trail maps. Half of them were helpful like "water source here is dry in summer" and half were just "this hike sucks" which made me laugh. I'd say the fun kind of notes are the ones that actually help the next person, and the annoying ones are the inside jokes nobody else gets.

Wait he drew DIAGRAMS on a napkin??