The most common and most likely answer to this crossword clue is the 5 letter word MAZER
I've seen this crossword clue in The Guardian
M
A
Z
E
R
Buddy explains!

The straight part
We know that "old wooden bowl" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case old wooden bowl = mazer.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 MAZER mean?
MAZER noun- The maple tree, or maple wood.
- A large drinking bowl made from such wood; a mazer bowl.