Aside: ended up in a restaurant/bar across sea (which is apparently a perfumed meat market) and turns out the manager is the son of a former employee of the ancient regime's embassy in London. He asked me where I am from and you know my answer ;) and he said "I was just in Tehran -- skiing in Dizin"  Last I skied there was in 79, the year he was born.
Anyway, the idea here is that you pay 25 bucks and get a sketchbook and scratch scratch with the Chinese extract to your heart's contentment. And then you hand back the book to the project and they scan it; display it; and take it on a world tour.
I have a gazillion sketchbooks in storage. I think I have found my archival unit ;)