Having blackened, cleaned (7)
I believe the answer is:
charred
'cleaned' is the definition.
(I've seen this before)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for charred that I've seen before include "Cleaned" , "Partially burnt" , "Scorched and blackened" , "Slightly burnt" , "what's black on surface" .)