In the folklore from the regions of Montenegro and Serbia, vampires are particularly fond of consuming fingers. To be rid of a vampire in a community, a severed finger is placed into a bag called a Vuval, tied tightly up, and thrown off a bridge and into a river. The vampire will want the finger so badly that it will jump in the river after the sack and consequently drown.

Source: Lincoln, Myth, Cosmos, and Society, 41-63; McClelland, Slayers and Their Vampires, 70