Emeralds by Night
Shit monsters are living creations of well, shit. Gabriel Kyle is something of an old hat at this shit, having faced and destroyed three shit monsters in his career.
In Gabriel's experience, shit monsters are shit animated by powerful Spirit magick, as well as Matter and Correspondence. The most direct way to destroy them is to counter the magick animating them, or to freeze or contain them. They can also be exploded, though this is a measure of absolute last resort.
Gabriel, Avery, and Amanda faced a particularly powerful shit monster at Pike Place Market. Ultimately Gabriel managed to destroy it with anti-magick, though not before it did massive damage. Gabriel stayed behind and allowed himself to be cleaned up along with the scene by the Technocrats.