Devilish practice removing sulphur after cleaner fuel ultimately is fraud (12)

I believe the answer is:

charlatanism

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'devilish practice removing sulphur' is the definition.
I can't judge whether this defines the answer.

'cleaner fuel ultimately is fraud' is the wordplay.
'cleaner' becomes 'char' (charwoman is a type of cleaner).
'ultimately' suggests the final letters.
'is fraud' becomes 'atanism' (I can't justify this - if you can you should give a lot more credence to this answer).
The last letter of 'fuel' is 'l'.
'char'+'l'+'atanism'='CHARLATANISM'

'after' acts as a link.

Can you help me to learn more?

(Other definitions for charlatanism that I've seen before include "Animal starch (anag) - quackery" , "Quacking" .)

I've seen this clue in The Times.

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