[cypher]

If you have to clean that often they're probably scent marking a lot all the time so it could just become a bit of a cycle, you clean they scent, unless it's the smell of pee?
Have you tried leaving it longer to see if the smell wears off with a little more time?
I'm sure the ventilation in a barred cage would probably help, a bigger cage might be better but then with a pair there is always the risk that a change like that could unsettle them enough to fall out so it's not an easy decision really.