Smutty material: this should be cleaned up! (5)
I believe the answer is:
filth
'smutty material' is the definition.
(I've seen this in another clue)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for filth that I've seen before include "Muck" , "Real dirt or obscenity" , "Disgusting dirt or obscenity" , "Repulsive dirt" , "Dirt, obscene talk" .)