I don't believe in magic, witchcraft, or whatever you want to call these silly tricks. The circle thing with the fingers is a simple trick, if enough people are involved. Some magicians, themselves, admit that magic is just a very cunning way of manipulating the laws of physics. The only place magic and sorcery exists is within TV world and one's imagination. Show me a witch that can create super potions, create dragons from straw, and/or can cause a person to levitate in an open field, and I'll jump into a pile of TV's. Heck, make that 5 piles of TV's.

EDIT: The thing with the "chanting", "Thin as *whatever it was*, light as a feather," is a simple psychological trick, if you will. If you think about or say one thing over and over in a certain position, you'll get sleepy.