http://www.rabbit.org/care/shavings.html
Good article about wood shavings and rabbits.
We have two plastic litterboxes, they were bought on-line and they are dog litterboxes. The Flemish girls are PBB’s. (Pretty Big Bunnies). We also have some cardboard boxes lined with oat hay, they like to jump in, eat the hay and/or the cardboard( !). A big litter box is in their pen, another in the hall, and the cardboard boxes are under the dining room table. We line the plastic litter boxes with newspaper and cover the paper with oat hay. We clean all the litter boxes daily. Sometimes we just throw the cardboard litter boxes away and start a new cardboard box.
We are so lucky to live near a feed and grain store whose customers are mostly horse owners, so the oat hay is much cheaper, and fresher, than the tiny expensive bags of hay at the pet stores. A big bag of oat hay costs $5.00. We use about 3 bags a week. A bale of oat hay costs $25 and weighs 100 pounds. There’s about 15 bags of oat hay in a bale, so it’d be much cheaper to buy the entire bale. However, a bale is pretty big and I don’t have anyplace to keep it at home, even if I could get it home.