The most common and most likely answer to this crossword clue is the 11 plus 1 letter word PRESSURING –
I've seen this crossword clue in The Sunday Telegraph
P
R
E
S
S
U
R
I
N
G
Â
â
€
“
Buddy explains!

The straight part
We know that "Using force" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case using force = pressuring –.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 PRESSURING – mean?
PRESSURING – verb- To encourage or heavily exert force or influence.
- An act or instance of pressuring.