Wholesale activity to remove dirt? (8)
I believe the answer is:
sweeping
I believe this clue is a double definition.
'wholesale' is the first definition.
('sweeping' can be a synonym of 'wholesale')
'activity to remove dirt?' is the second definition.
(Other definitions for sweeping that I've seen before include "Extensive" , "Brushing or ignoring distinctions" , "Wide in range or effect" , "not very specific" , "Wide-ranging and comprehensive - also cleaning?" .)