Sorcerers are supposed to use bodily refuse in pursuing their nefarious desires. Certainly in this sense excremental magic ministers to its user's desires, but information about sorcery is usually given from the alleged victim's point of view. Vivid accounts of the materia medica of sorcery can always be had from supposed victims. But recipe books of charms dictated by confessed sorcerers are rarer. It is one thing to suspect that others are using bodily refuse unlawfully against oneself, but this does not mean that informants think of these materials as available for their own use. So a kind of optical delusion makes what often belongs on the negative side of the balance sheet appear on the positive side.