Moist sea creatures British caught, not Germany -- they won't go off (4,6)

I believe the answer is:

damp squibs

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'they won't go off' is the definition.
(term for a firework which won't go off)

'moist sea creatures british' is the wordplay.
'moist' becomes 'damp' ('damp' can be a synonym of 'moist').
'sea creatures british' becomes 'squibs' (I can't explain this - if you can you should give a lot more credence to this answer).
'damp'+'squibs'='DAMP SQUIBS'

'caught not germany' acts as a link.
This may not be correct. Some or all of it may be part of another bit of the clue.

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I've seen this clue in The Telegraph.

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