Having got in, this spinner could get you out straightaway (9,4)

I believe the answer is:

revolving door

'this spinner could get you out straightaway' is the definition.
The definition suggests a singular noun which matches the answer.

'having got in' is the wordplay.
I cannot really understand how this works, but
'in' is within the answer.
This explanation may well be incorrect...

(Another definition for revolving door that I've seen is " Rotating entrance".)

I've seen this clue in The Times.

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