MTSs are too hard to eat for many fish. They breed according to your overfeeding. As Primus said, they stir the sand and separate it from detritus. With a decent water movement in your tank and smart filter outlet (near substrate, obviously not overflow), your filter will easily catch all detritus and trap it.
i have a baby hoplo cat in my 10 gal with sand.
he dives into the sand with his mouth looking for stuff.sturs it up a bit.
i can vid it if ya wanna see him do it.
and i dont think anything eats poop lol