Cockney's hair dressing publication is an attractive item (3,6)
I believe the answer is:
bar magnet
'an attractive item' is the definition.
(magnetic attraction)
'cockney's hair dressing publication' is the wordplay.
'cockney's hair' becomes 'barnet' (Barnet Fair is Cockney rhyming slang for hair).
'dressing' means one lot of letters goes inside another (inserted letters are dressed or clad in others).
'publication' becomes 'mag' (abbreviation for magazine).
'barnet' going around 'mag' is 'BAR MAGNET'.
'is' is the link.
(Other definitions for bar magnet that I've seen before include "Attractive thing" , "Oblong attractor" , "attracting stick?" , "Attractive 19 ac [ROD]" , "Attractive block of metal" .)