Redskinluver:
On the other hand, takes little imagination to realize that a spanking husband might use her own hairbrush on her. And in the bedroom good possibility it would be on her bare bottom!
Of course, it's equally possible for a spanko-dominant wife to employ her husband's own leather belt on his bare bottom, especially since an initial step in exposing the posterior of someone wearing a belt would be at least unbuckling and loosening it--quickly pulling it free from the loops in the pants would be a natural process after that, and to a person accustomed to being strapped with a belt, that sliding sound could be highly unnerving.
These days, males having their own hairbrushes (due to longer masculine hair styles being popular) and females wearing their own leather belts (due to pants being acceptable feminine clothing) means that a husband/boyfriend could be spanked with his own brush and a wife/girlfriend with her own belt, although the traditional associations still seemingly do linger among spankophiles.
One key advantage of a hairbrush is that it generally can be left out in the open in various rooms of a house, as a reminder/symbol of its owner's disciplinary authority, without appearing to be particularly out of place from the perspective of visitors. A leather belt laying on the coffee table in the living room, however, might raise some eyebrows even on the part of 'vanilla' guests...

--C.K.