Office workers' duck croaks having swallowed article (3,6)

I believe the answer is:

tea ladies

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'office workers'' is the definition.
I know nothing about this answer so I cannot tell whether it can be defined by this definition.

'duck croaks having swallowed article' is the wordplay.
'duck' becomes 'teal' (teal is a type of duck).
'croaks' becomes 'dies' (I've seen this before).
'having swallowed' is an insertion indicator.
'article' becomes 'a' (the indefinite article in English).
'teal'+'dies'='tealdies'
'tealdies' going around 'a' is 'TEA LADIES'.

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I've seen this clue in The Independent.

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