I used to use 2 layers of towels underneath, and they lasted a week before needing changed. I'm using puppy pads now which also last about a week for me, but that varies from person to person.
I have 2 cat litter trays with newspaper and wooden cat litter pellets, which I put hay into to keep it off the fleece, as it can be a pain in the backside otherwise.
I do a poop run once a day, though I use a Dyson DC34 Animal for it, so hair on the fleece is at a minimum when it comes to the fleece being changed.
As much as I find fleece annoying to change and wash, I wouldn't have my lot on anything else.