Massage the tough part (3)

I believe the answer is:

rub

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'massage' is the definition.
(rub can mean to massage)

I don't understand the remainder of the clue.

(Other definitions for rub that I've seen before include "Ay, there's the - (Hamlet)" , "Irritate-...the wrong way" , "Remove marks - ... out" , "Abrade" , "Work in" .)

I've seen this clue in the Evening Standard.

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