You can get puppy pads at Walmart or any other store that has a pet department. They are potty training pads for dogs. I put down puppy pads on the bottom, then newspaper, then one layer of towels, then fleece. I wash my entire cage about every 5 days. When I change it I leave in any puppy pads that have not been soiled (usually most of them are not), put the towels in the washer and shake out the fleece and put that in there also. I put in detergent and about half a cup of vinegar to the load. I wash and dry and set my cage back up. Many people have more than one change of fleece and towels so they can just change it when needed and not have to do the laundry right then. I just give my boys a couple hours of floor time while their cage is being cleaned.
I do have a litter box. It is a good idea to put a littler box under any hayrack you may have. The pigs tend to spend alot of time in there so the box will hold some of their droppings. You do have to vacuum out the poos every night or the cage gets filled with poo fast. I have a little hand held vac that I use for that. I try to vaccuum it in the morning and evening. I have found if i let it go for too long (3 days was the most when I was sick) It gets very poopy very fast. I probably had a good half a lunch bag full of poo by the time I was done cleaning it.
Also I have aspen in my littler box. It is kind of a pain to get off the fleece so i am going to switch over to carefresh or something else. Hope that help a little bit!