really? I remeber someone telling me you can keep the aspen in there up to 6 months! Actually it says that on the bag!! I mean if you think about it, how dirty can it really be? If you spot clean as nessacarey, and don't let things linger too long I can see it lasting that long. I mean like I said I have had it in there since oct, and there are NO smells. Actually its going on 6 months on march. As soon as march comes I'll change it. Anyone else use aspen? I know paper towels are good too, but mine seem to like to dig themselves into the aspen im gonna stick with this.