My pig likes blueberries 
I tried fleece in the past but only the coarse one worked, the very plush fleece kept the pee on the top layer so meant my piggies got soaked bellies.It was thrown out daily (cheapie Primark ones after Christmas sales)
I use puppy pads/newspaper/hay , rolled up and replaced every day.
My carpets within a 10 foot radius of the pigs' room get strewn with hay, my washing machine does not want to join in the fun that the vacuum cleaner has.
I tried hay cookies before but my pigs like to sleep in a haybed so whatever makes them happy 
Old piggies can go a bit scrawny , keep a check on his teeth, eating and pooh output.
Our GP1 went really ratfaced (no offence to rats) but was really bright to the end, just lost condition.