Here's one you're likely to encounter: shide--the folded paper that is attached to the straw rope (or shimenawa) that marks the boundary of a sacred space (you can see two of them in between the rope tassels in the photo here).
Shide can also be attached to a willow branch, and used as a harai gushi. This is often translated as "shaking stick"--sweeping the stick with the shide attached has the effect of purifying a space--because the word harai can mean "shaking," but guess what--that's right, another homonym at play. Harai also has the sense of exorcism. So the question is, why does paper folded in a zig-zag pattern function to exorcise powers that are improperly situated? Idle speculation in class is welcome.