A more thorough explanation:

A trebucket, also known as a castigatory, is a historical device used for punishing scolds by repeatedly plunging them underwater. It was used by the ancient Saxons and is mentioned in the Domesday Book. The device was also used to punish bakers and brewers by ducking them into "stinking water".

According to William Blackstone's Commentaries on the Laws of England, a common scold, if convicted, shall be sentenced to be placed in a trebucket, castigatory, or cucking stool, which in the Saxon language signifies the scolding stool. The residue of the judgment is that when she is so placed therein, she shall be plunged in the water for her punishment.

The use of the trebucket was a common form of punishment for scolds and other offenders in medieval times. The punishment was meant to humiliate and shame the offender in front of the community.

These examples illustrate how the trebucket was used as a form of punishment for scolds and other offenders in medieval times. The device was used to publicly shame and humiliate the offender, and the punishment was often carried out in front of a crowd.