Inexpensive but simple cat bedding?

I have 5 kittens at the moment, and all of them have pretty upset tummies. They've gone to the vet and been dewormed/checked over, but it hasn't helped much. I recently introduced them to a new food that will hopefully help. I rescued them from a farm where they were not fed very well, if at all, so the abrupt change in diet (I wasn't able to get some of their old food) has caused very upset tummies. A few do them are doing better, but I'm needing some ideas!

Right now they sleep on an old blanket of mine in the garage. I don't own a house, still live with my parents, and they're practically banished from the house. The garage is closed and no cars come and go so predators cannot come in and they are safe. My problem is they soil the blanket quite often. I'm not allowed to put it in the washer, so I'm wondering if there are any inexpensive bedding ideas I could use for them? I don't really want to use hay because I want too avoid irritating their eyes... I can't think of much else. Anybody have any ideas? Any input on what I could feed to help their upset stomachs?

We use towels for bedding with our sick kitties. Hotels and the like donate them once they start to get worn out. Puppy pee pads might also be an option (or newspaper) as you can throw away and replace as needed.

If you have a Dollar Tree near you, they sell puppy pee pads.  I think there are four to a pack for $1. 

Just curious why you are not allowed to put the soiled towels in the washer?  You could always go to a laundromat. 

Maybe try the pine or cedar chip bedding that they use for small animals like hamster, I know at the Wal-mart near me they sell large packs of it for around $10. The only problem that I can see with hay, chips, newspaper, or puppy pads is that it may seem like a litterbox filler to the kittens and encourage them to use it as a potty.

If you do manage to get to the laundromat to wash it add some enzyme cleaner to the wash so that the smell is completely removed.

I'm not sure where you are located, but I've purchased plain white towels from a "dollar store" type of place. The quality is really cheap, but I bought them with the intention of throwing them away. I would recommend plain white...not dyed, painted, or embellished.

Is the garage relatively warm? The reason I am asking is because any kind of fabric material will hold moisture and cold...not good for kittens. They need to stay warm.