Drawing cleaner fuel (8)
I believe the answer is:
charcoal
'drawing' is the definition.
(charcoal is a kind of drawing)
'cleaner fuel' is the wordplay.
'cleaner' becomes 'char' (charwoman is a type of cleaner).
'fuel' becomes 'coal' (coal is a kind of fuel).
'char'+'coal'='CHARCOAL'
(Other definitions for charcoal that I've seen before include "Fuel made from burnt wood" , "Carbonised wood" , "It's used in drawing and barbecues" , "Black carbon from burnt wood" , "Black residue of burnt wood" .)