Crossword Genius

Revolutionary ops began working on gallon waterproof container (6,3)

Ross

I believe the answer is:

sponge bag

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'waterproof container' is the definition.
The definition suggests a singular noun which matches the answer.

'revolutionary ops began working on gallon' is the subsidiary indication.
'revolutionary' says the letters should be written in reverse.
'working' is an anagram indicator.
'on' means one lot of letters goes inside another.
'gallon' becomes 'g' (this could be a standard abbreviation which I don't know about).
'ops' backwards is 'spo'.
'began' is an anagram of 'nebag'.
'nebag' placed around 'g' is 'ngebag'.
'spo'+'ngebag'='spongebag'

Can you help me to learn more?

(Other definitions for sponge bag that I've seen before include "Container for toiletries" , "Carrier for toiletries" , "Shower accessory" , "Carrier of toiletry items" , "Container for ablutionary articles" .)

I've seen this clue in The Telegraph.
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