An excellent point, McDuff. I was going to run it through the Blad, but now I'm going to try it first with my trusty, & snappily named, Houghton-Butcher Ensign Carbine Tropical Model. No fears of the Washi fouling the H-B EC(TM) pressure plate - it doesn't have one.
After I've banged the paper through the soup, I'll have a better idea of thickness, potential for debris falling off etc. If I like the Washi effect, but decide not to put it through the Blad - well, that will be a top reason to persuade Mrs Zapsnaps that I need another MF camera for this sole purpose. By buying another MF camera, I may well be saving the cost of an expensive Blad repair job.