Spoil opera, turning it into ridiculous shell (9)

I believe the answer is:

radiators

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'spoil opera turning it into ridiculous shell' is the definition.
I can't tell whether this definition defines the answer.

'opera turning it into ridiculous shell' is the wordplay.
'opera' becomes 'aida' (Verdi opera).
'turning' shows that the letters should be reversed in order.
'it' becomes 'tor' (I can't explain this - if you can you should give a lot more credence to this answer).
'into' indicates putting letters inside.
'shell' says to hollow out the word (remove centre letters) (only the shell of the word is left).
'ridiculous' with its middle taken out is 'rs'.
'aida' back-to-front is 'adia'.
'adia'+'tor'='adiator'
'adiator' put inside 'rs' is 'RADIATORS'.

Can you help me to learn more?

(Other definitions for radiators that I've seen before include "Heaters" , "coolers" .)

I've seen this clue in the Sydney Morning Herald.

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