Lin, I really don't know what ingredient it is. I got the idea from one of those e-mails that's circulated among friends. This one listed dozens of things dryer sheets could do in addition to being used in the dryer. I remember getting lots of good ideas from it, such as putting dryer sheets (unused) in the bottom of garbage cans and waste baskets to absorb odors and slipping them under pieces of furniture like couches and chests to kill spiders, fleas, and other bugs. I don't remember whether the flower pot thing was on the list or if I just thought of it because of the tip about the furniture. I have lots of earwigs and sowbugs here, and they like to enter pots through the drainage holes.
