What figure of speech is used in the expression "...wouldn't have to clean 'dishes', as folks uncharitably say about washing corpses."

A euphemism is a figure of speech in which a mild, indirect, or less harsh expression is used in place of one that is considered too blunt, unpleasant, or offensive. In this expression, the word "dishes" is used euphemistically to refer to corpses. Rather than saying directly that someone washes dead bodies, the expression substitutes the word "dishes" - an everyday, innocuous term - to soften the disturbing reality of the task.

The text itself acknowledges the euphemistic nature of the expression with the phrase "as folks uncharitably say," indicating that this is informal, colloquial language that people use to describe the work of washing corpses without having to state it plainly. The quotation marks around "dishes" further signal that the word is being used in a non-literal, substitutive way.

This is not personification because no human traits are given to a non-human thing. It is not hyperbole because there is no exaggeration. It is not an allusion because the expression does not reference a specific well-known work, person, or event. The device at work is the deliberate substitution of a gentler word for a disturbing concept - the defining characteristic of euphemism.