I don't mean to sound stupid, but using fleece liners is a new concept to me and somebody said you just shake out the poop, but don't the chins pee right through the fleece or do they use litter boxes??
The liners are usually made with an absorbent material between the layers of fleece, which soaks up the urine. Some people use littler pans in addition to the liners, but it's really a personal choice. You shake off the poo and hay before you wash them, and change them out somewhere around every 3-5 days.
Our liners have a layer of fleece on the top and bottom and a towel that is sewn in the middle. We shake ours out and put new liners in every two days(I have made two liners per cage). I don't use a litter box with our liners which is one reason I change them more often.
We make all of our own, there are quite a few people here that make & sell them myself included.
OH OH! I have the instructions for the fleece liners that someone posted on CnQ saved to my comp if anyone wants me to post it. Whoever made it can come forward and reply to it, it's not mine and I'll admit it but I saved it for future reference.