### Clue: Cleansing moggies is mostly difficult inside (9)
### Answer: CATHARSIS 
 ### Explanation: Definition: Cleansing
  [CATS("moggies" is British slang for "cats") + IS] **containing**(…inside) HAR{"hard"(difficult) **minus** its last letter(mostly)}
Answer: The purging,cleansing,relieving of emotional tensions, especially through certain kinds of art, such as music or tragic drama.  Or, at the other extreme, literally, it is the purging of the bowels.