Here's the scene that met my (admittedly twisted) mind on first reading "The Musical Tampon Effect":
A house full of women who, for some reason or another, have synchronized schedules and draw from the same pool of tampons. One month -- let's say it's December and they're snowed in, so they can't get to the corner store -- they find that there are only 5 magic wands left in the box the 6 of them share. That's the cause.
Not immediately sure how to proceed, the women entertain a few suggestions before collectively deciding to leave it up to chance and play a game of musical tampons. I suppose the effect would be that the odd woman out is forced into making some amazing leaps in the field of engineering -- I think it's probably best I just leave all that up to your imagination, though.