Are you ready for this? Simply cut up cardboard boxes to fit the bottom of the nest boxes (i often make them a little big to go up the sides a bit.) fill with shavings. To clean... pop them out and replace or flip them if they aren't too dirty or wet....refill shavings.....toss out cardboard. Zero $ and very little time. I keep a bunch of precut cardboard in the coop at all times. I use scissors to pop them out cause i keep a pair in the coop to cut bags of food.