With mummification you can only reach the feet! How boring is that! 🙂
I would say not at all. I'd be perfectly happy being limited to a pair of pretty ticklish feet. Of course, it all depends on one's personal preferences.
Well, if I was tickled on my feet only, I wouldn't be able to stand it very long. Plus, there's just so much more that's worth tickling. 🙂