I'd avoid shavings/saw dust - they are not recommended for small animals such as guinea pigs or rabbits as they can cause skin, eye, nose and respiratory irritation as it's untreated timber and the phenols in the timber can become acidic when in contact with urine. Apart from that the small particles can get stuck in eyes and noses.
I'd suggest you use litter trays and line them with newspaper and then hay. If you want to use a litter then add something like Megazorb, Carefresh, Yesterdays News and then add the hay.
By doing this it will encourage the rabbits to use the tray and not the corner of their accommodation.
We line our hutches/sheds with lino to prevent damage etc, and then use newspaper to line the area. This gives the rabbits somewhere clear of bedding to lie down.