It was once commonly believed that a witch's power could be nullified by blooding or burning her blood. Convicted witches were "scored above the breath" (slashed over the nose and mouth) and allowed to bleed. Sometimes witches blooded this way bled to death.

Anouther method was used both as torture of witches and a form of medical use. The leech would suck out the blood, and depending on how many, kill the person. A friend told me there was anouther method where it involved the victim swallowing leeches whole so they could suck the blood painfully from the inside, but i;m not sure thats entirely true. If anyone has any info on it tell me.