The most common and most likely answer to this crossword clue is the 9 letter word LATHERING
I've seen this crossword clue in Financial Times
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More clues leading to the result LATHERING
Buddy explains!

The straight part
We know that "getting /foam/y" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case getting /foam/y = lathering.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 LATHERING mean?
LATHERING verb- To cover with lather.
- To beat or whip.
- To form lather or froth, as a horse does when profusely sweating.
- The act of lathering; a covering with lather.