“Unuseless” Invention #281:
Back Scratcher’s T-Shirt™
The trick is NOT to itch where you can scratch; it’s to get scratched where you itch!
A number of (non-chindogu) implements exist to try to help us address itches that we can’t reach. Still, wooden claws just can’t quite provide the same relief that a skillful human finger will, and hence the phrase “you scratch my back, I’ll scratch yours.”  This reciprocal arrangement often provides a few seconds of glorious relief, but is typically followed by several more of frustration over the fact that the “you”s of this world never seem to know quite where the itch is.  The “we”s can explain to some degree–“up, down, more to the right, no the other right”–but itches move, and pinning one down is a lot like sinking a battleship in a sea that you can’t quite see.  At least that’s the way it used to be.  Now, it’s more hits and fewer misses with the Back Scratcher’s T-Shirt.  It is expected that people with perpetually itchy backs will take to wearing shirts like these at all times and soon be instinctively aware of all coordinates with the grid committed to memory.  Meanwhile, for the occasional itcher, the T-Shirt™ comes with a handy cheat sheet.