In literature, the term sludge serves as both a literal descriptor of thick, unwanted industrial refuse and a powerful metaphor for decay and moral ambiguity. In technical and environmental contexts, it denotes the byproduct of chemical or filtration processes that must be methodically managed, as in discussions of wastewater treatment or industrial residue [1], [2]. Conversely, in more lyrical or satirical works, sludge transforms into a symbol—sometimes even a personified character like "Mr. Sludge, the Medium"—embodying both the unattractive aspects of decay and a hidden, more complex truth beneath the surface [3], [4], [5]. In one narrative instance, a character even speaks of drowning another in sludge, underscoring how this murky substance can evoke both literal and figurative depths of corruption [6], [7].