Changes his wet flannels (6)
I believe the answer is:
whites
'flannels' is the definition.
(I know this)
'changes his wet' is the wordplay.
'changes' indicates anagramming the letters.
'his'+'wet'='hiswet'
'hiswet' with letters rearranged gives 'WHITES'.
(Other definitions for whites that I've seen before include "that's what batsmen are into" , "Outfit for cricket" , "club" , "Not the yolks" .)