Poor Agnes beset by gold bits of furniture which took some cleaning (6,7)
I believe the answer is:
augean stables
'which took some cleaning' is the definition.
I can't judge whether this definition defines the answer.
'poor agnes beset by gold bits of furniture' is the wordplay.
'poor' indicates an anagram.
'beset by' is an insertion indicator ('beset' could historically mean 'cover').
'gold' becomes 'Au' (Au is the chemical symbol for gold).
'bits of furniture' becomes 'tables' (table is a type of furniture item).
'agnes' with letters rearranged gives 'geans'.
'au'+'tables'='autables'
'geans' going inside 'autables' is 'AUGEAN STABLES'.
Can you help me to learn more?
(Other definitions for augean stables that I've seen before include "One of Hercules' labours" , "that needed flushing out" , "filthy old place" , "Hercules cleaned them" .)