I've used fleece in the indoor cages in winter but I don't wash it (I really don't want my washing machine clogging up )
Things VetBed are ££ but I can see they'd be brilliant for older or arthritic animals.
I;ve tried all types of bedding, mine like sleeping in hay, I'm not keen on loose hay indoors .
Last year , the plastic based cage had wood pellets (rodent safe) newspaper , fleece under the pigloo and hay cookies.
The C&C had cardboard, newspaper , a soft mat to sleep on with puppy pads/newspaper and haycookies.
So each cage had a soft sleep area.
I rolled everything up and replaced it daily, bought cheap fleeces from Primark or Ikea and cut them up.
The only way my rodenty ones are comfortable is with daily fresh bedding so the re-use fleece isn't for me, but I do lnow some owners like it to wick the pee through (you'd need a base absorbant layer) and sweep the droppings off.
Our pigs sleep in the small bedroom , I need to get them out in the Pighouse (fresh bedding) and clean the indoor cages, and feed them before breakfast and getting myself to work and everyone out the house.
Its a case of trialling and see if it suits you and your pigs.