Most of my cage has fleece liners. I have a litter box in the loft and one the main level in which I put a layer of Petco
SoPhresh over which there is a generous amount of hay. My cavies have always loved the setup as it enables them to do two things at once. Because they also seem to like to sleep in the litter box, it has to be tided a couple of times a day to remove the soiled hay and poops. The litter seems to last a long time as we generally just scoop out the soiled area, spray with
Cage Clean and add fresh litter as required.
I've tried a lot of different products and the
SoPhresh is both cost-effective and good at controlling odor. I buy either the pellets or crumbled paper variety.
https://www.petco.com/shop/en/petcostore/product/so-phresh-paper-pellet-small-animal-litter
https://www.petco.com/shop/en/petcostore/product/so-phresh-crumbled-paper-small-animal-bedding