The most common and most likely answer to this crossword clue is the 2 plus 4 plus 2 plus 2 plus 5 letter word BY HOOK OR BY CROOK
I've seen this crossword clue in The Times
B
Y
H
O
O
K
O
R
B
Y
C
R
O
O
K
Buddy explains!
The straight part
We know that "using perhaps dubious means" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case using perhaps dubious means = by hook or by crook.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.