Cleaning implement that in Paris say is used in court (8)
I believe the answer is:
squeegee
'cleaning implement' is the definition.
(squeegee is a kind of cleaning implement)
'that in paris say is used in court' is the wordplay.
'that in paris' becomes 'que' (French for 'that').
'say' becomes 'eg' (both can mean for example).
'is used in' indicates putting letters inside.
'court' becomes 'see' (both can mean to date somebody).
'que'+'eg'='queeg'
'queeg' going within 'see' is 'SQUEEGEE'.
(Other definitions for squeegee that I've seen before include "Window cleaner" , "Window cleaner's rubber-edged tool" , "Implement used by window-cleaners" , "Rubber-edged too, for cleaning windows say" , "Cleaning implement" .)