Use revolting fabrication — it could help you sound believable (6,6)

I believe the answer is:

silver tongue

'it could help you sound believable' is the definition.
(someone with a silver tongue is a good liar)

'use revolting fabrication' is the wordplay.
'fabrication' indicates an anagram.
'use'+'revolting'='userevolting'
'userevolting' anagrammed gives 'SILVER TONGUE'.

I've seen this clue in The Guardian.

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