What are the ingredients in itching powder?

I had read on one site that said it uses finely ground fiberglass. However, I am not sure how official that one was. I tried to see if I could find an MSDS for it. Theoretically, there should be one. However, the Itching Powders I found in Froogle were made outside of the country (at least on the packages that I could read where it was manufactured).





I found another site that tells how to make it yourself using hairs off of a plant.


http://www.blamepro.com/how/how1.htm





I even found one site that said that it was made from hairs from a spider. That was a dead link, but I was able to read it in the decription. A tarantula has these hairs that are called nictating hairs. They can be used to repel animals trying to eat the tarantula. They are rather itchy.





I also remember a cactus that had extremely small hairs on it that felt like those from the tarantula.