Lamp's laboriously cleaned out with a soft touch (7)
I believe the answer is:
lightly
'with a soft touch' is the definition.
(done with a light or soft touch)
'lamp's laboriously cleaned out' is the wordplay.
'lamp' becomes 'light' (I've seen this before).
'cleaned out' means to remove the middle letters.
'laboriously' with its middle taken out is 'ly'.
'light'+'ly'='LIGHTLY'
(Other definitions for lightly that I've seen before include "without good reason?" , "Softly" , "in delicate fashion" , "easily" , "with little reason" .)