You can use linolieum (sp?) as an alternative, I believe.
As far as towels, you can use them as an alternative to bedding, but it's best to use 3 layers of protection.
For instance, I use a mattress pad (that I cut up to fit inside the coroplast), 2 towels (cheap thick ones that I got from Big Lots for 8 bucks each, they're also REALLY long), and a layer of fleece that I got from Joanne Fabric.
The towels and fleece are so thick that the urine doesn't even get as far as the mattress pad. All of the urine soaks up in the towels that I have laid down.
I have 2 extra changes of fleece and 2 more towels so that I don't have to keep washing and changing out the fleece/towels every time. That way whenever I go to wash the used and dirty ones, I already have a clean change of fleece and towels ready to go down.
I change out the fleece every week, every Sunday in fact, and I spot clean 2 times a day with a hand vaccuum to get the poop. It works great. The only way to clean the fleece and towels of urine is to wash them in fragrance free detergent with no fabric softener.
You also have to wash the fleece SEVERAL times to make it absorb the urine. You can test it by putting water on it. If the fleece doesn't absorb the urine, it will sit on top and get the piggy's bottom all wet and dirty. So it's important to make the fleece wick properly (or absorb properly). I love the fleece, I am glad I don't use that gross bedding, plus the spot cleaning only takes about 5 minutes or less to do and I have a 2x4 CC cage with a 1x2 loft. It's easier and cheaper than bedding.