Lightly damp the covers with a spray bottle like this http://www.ebay.co.uk/itm/PLASTIC-HAND-SPRAY-BOTTLE-300ml-WATER-HAIR-GARDEN-Y-/140630328541?pt=LH_DefaultDomain_3&hash=item20be3884dd
Then with a marrigold type of rubber glove rub your hand over the seat covers and the dog hairs will stick to the glove
paul, November 2011