Perhaps crude and dirty, but not salacious ultimately (3)
I believe the answer is:
oil
'perhaps crude' is the definition.
'oil' can be an answer for 'crude' (crude oil). I am not certain of the 'perhaps' bit.
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for oil that I've seen before include "What can be extracted" , "Lubricate; fuel" , "Greasy liquid" , "Type of fuel" , "eg Olive" .)