Cauldron of atonement

A Raxacoricofallapatorian insult was "May your mother boil in the cauldron of atonement". (PROSE: The Monsters Inside)

The Raxacoricofallapatorians had the death sentence, in effect as late as the 2000s, for dangerous criminals like the Slitheen, which was carried out in a gruesome way. The criminal would be lowered into a cauldron of acetic acid, which would then be heated to boiling. The acidity of the solution was formulated to dissolve the skin, allowing the internal organs to drop into the liquid "soup" while the condemned was still alive, resulting in a slow and painful death. (TV: Boom Town) At some point, however, this sentence was lifted, with captured Slitheen instead being taken into incarceration. (AUDIO: The Taste of Death)