File their nails. My last "coating" on my 08 K1200GT (before 2nd gear started popping out) was to tile it with sandpaper. It was grey-colored skate board traction tape. 4" wide, sticky backed, I cut 2:1 rectangles and covered it like the space shuttle. Replaceable tiles if damaged, and as hard as the road. I covered the tank in 3m's calendared-vinyl non-skid, and this is why the entire project worked phenomenally well. I recently covered my K1600GT's tank with the traction tape, and it SHREDDED my riding gear. Lesson: you can indeed sandpaper-cover your bike, but not the panels that the rider contacts.

Friends would walk up, laugh, and do a little nail-file when they saw it.