The most common and most likely answer to this crossword clue is the 7 letter word POMADED
I've seen this crossword clue in The Guardian
P
O
M
A
D
E
D
More clues leading to the result POMADED
Buddy explains!
The straight part
We know that "Smooth, like well-oiled locks" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case smooth, like well-oiled locks = pomaded.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does POMADED mean?
POMADED verb- To anoint with pomade; to use pomade to style (hair).