Dont use pieces as accessories (5,5)
I believe the answer is:
spare parts
'accessories' is the definition.
(I've seen this before)
'dont use pieces' is the wordplay.
I cannot quite understand how this works, but
'use' could be 'spare' (sparing is a kind of using) and 'spare' is found in the answer.
'pieces' could be 'parts' ('part' can be a synonym of 'piece') and 'parts' is found in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
'as' is the link.
Can you help me to learn more?
(Other definitions for spare parts that I've seen before include "Replacement components" , "offered for replacements" , "such may effect repair" , "accessories" , "Don't be merciless on everything" .)