Another visit from Head Office on 13-05-2012 "Oxford town and gown race"

Chris, I believe larger DIY stores sometimes sell rods singularly, and you may be able to get brush heads as well. Try the trade places too like Jewsons, Travis Perkins, Builder/Plumb centre etc.

Unfortunately I'm fairly new to Oxford's famous Oxford so am not too familiar with the location of such establishments.

B&Q* cowley center, Travis Perkins Cowley Road and Botley

Wcks, Botley, Jewsons, Wheatley, HomeBase on the ring road, Screwfix on the ring road nr BMW plant. how sad am I ;-)