I have had my girlies that are now 5 days old on paper towels and doggie pee pads. I am going through them like crazy! So I was wondering if it was time to use the pine shavings. I have read anywhere from 2 days to a week. When I start the shavings should I keep the paper towels on there for one more day? I also have aspen that is pretty chunky. Would it be better to use that since it can't be eaten? I am worried to use it since some of it can be really sharp. I use it for my chinchillas so I have it handy!