Nice one to choose to extract sewer's product? (6)
I believe the answer is:
unpick
'extract sewer's product?' is the definition.
(as in to unpick a bit of sewing, something sewn)
'nice one to choose' is the wordplay.
'nice one' becomes 'un' ('one' in French, eg in Nice).
'to choose' becomes 'pick' (picking is a kind of choosing).
'un'+'pick'='UNPICK'
'to' acts as a link.
(Other definitions for unpick that I've seen before include "analyse meticulously" , "subject to close scrutiny" , "Undo (stitches)" .)