If you go with fleece liners and your chin is not pee trained you do need some sort of absorbent layer. Some people use quilt batting, others use a towel, personally I just use more cheap fleece, so my chins are sitting on 3 layers of fleece. That way if the chins decided they want to chew through the fleece one day it's just more fleece inside, so nothing dangerous. Fleece is the only safe fabric, but only safe if you chin doesn't chew it, it doesn't unravel like other fabric so you can generally remove it before they chew and swallow too much to cause a problem. Since it doesn't unravel or shred most chins just do test nibbles, find it boring, and leave it alone.
Make sure you wash the fleece before using it, and only use vinegar in the wash, no detergent or fabric softener (they can coat the fleece and make it water repellent). It's not bad in terms of absorbancy if you go 3 layers thick, but you do need to change it a couple times a week if your chin is not pee trained. Fleece doesn't mask odor at all like shavings do so for some people they find it can stink after just one day. If pee trained you'll need to change the litter box everyday, but changing the fleece once a week is fine.
Pee training for some is as simple as putting a dish with shavings in the cage where they pee. For others you need to train them by slowly remove the shavings over the course of weeks until they are peeing in just one spot. Not all chins can be pee trained though, and it can take time. You could have one like my guys who just pee where ever they feel like it (often over the edge of a shelf). Also some chins can be pee trained for awhile and just decide one day they don't feel like peeing in the box anymore for no reason.