"Very low tech, but could you use gauze or moleskin with micropore tape?  Or just put a strip of Opsite tape over the area?  They're more low-tack but they do stay on, and if you do the Opsite tape only you'll still be able to see through it, although blurry.   Regarding the prosthetic idea below, I'm a film/tv makeup artist, and you have 3 choices of material - foam latex, which is heavy, soaks up sweat, and very hot, gelatin, which will melt in heat, and encapsulated silicone, which is crazy delicate.  Plus you'll need much stronger adhesives to keep any of them on.  Unless he's suggesting a mold made of your face and then 3D printing something off of that.  Based on where you are I can help you find a makeup effects artist to do a lifecast, if you're into that idea."

"Body wash is much more popular in Europe since in many cases, instead of standing under streaming water the whole time, they wet down, turn off the water, lather up (easier with a liquid or gel than a bar of soap) then rinse off.   At least that was my experience when I lived in Sweden and Germany.   Hated body wash then, hate it now too."