Hey, I'm from a guinea pig forum. Most people sew 1 or 2 layers of uhaul between 2 pieces of fleece (so that it's fleece-uhaul-uhaul-fleece). The fleece on both sides protects the uhaul from disintegrating too much, many people have the same liners for over 3 years (of course guinea pigs don't chew as bad as rats do)
Most people wash it in hot water with bleach (chlorine is fine and won't discolor fleece) and dry on hot. The fleece has to be washed and dried (without dryer sheets) so that it will wick liquid through, otherwise pee will sit on top of the fleece and won't get absorbed.