Have you figured out where the odor is coming from? I hate to suggest this... but you might have a dead mouse in the walls! We had this happen the winter before we got Allen (in fact, that is the ONLY reason I was able to convince hubby to get a cat -- to get any mice that might think our home looks like a good home for them) Field mice go into ANY home -- clean or not -- so this is no bearing on you and your housekeeping. Keep an eye for any signs of the critters. Its common at this time of year for such a thing to happen.