Pelting Ed turned out to be exhausting (9)

I believe the answer is:

depleting

'exhausting' is the definition.
('deplete' can be a synonym of 'exhaust')

'pelting ed turned out' is the wordplay.
'turned out' is an anagram indicator (turn out can mean to organise).
'pelting'+'ed'='peltinged'
'peltinged' with letters rearranged gives 'DEPLETING'.

'to be' acts as a link.

(Another definition for depleting that I've seen is " Using up".)

I've seen this clue in The Mirror.

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