Horse bedding pellets are 100% compressed pine. We've used them on the coop floor since we started raising chickens again 8 years ago. We've started using them in the brooders this spring. Gamer changer there!
I started putting those in the nest boxes that they perch in front of so I didn't have to clean them so often. (Silkies like wide perches.) Then I found out they were using those two over the other five with straw in them to lay their eggs. No, they don't touch them, just scratch them around saving me the job of that. The pellets dry out the poops, so eliminates smells and humidity. I just stir them now and then if I see the poop building up, or use a little shovel and take out the dry poops. On the floor we do nothing, just change them yearly, in the spring.