Abstract: There is disclosed a method of mechanically washing an animal casing such as a bung. The method involves placing the casing on an elongate support element so that the element extends through the casing, the element having a duct or ducts for washing liquid and outlets for discharging the liquid inside the casing. With the casing in place, washing liquid can be caused to issue from the outlets under pressure so as to wash the interior of the casing. There is also disclosed a machine for washing such casings, the machine essentially consisting of a number of such elements which can be loaded with casings in a loading zone, a supply means for supplying washing liquid to the ducts of the elements in a washing zone, and a transport means for transporting the elements in rotation between and through these zones.