I have tried it, I thought I was being thrifty and could save a few dollars.
Well first off it made a much bigger mess, second it did not absorb and last it did not cover the odor of the rabbit smell.
Same with a cat, the paper shredd makes a much bigger mess even if mixed with regular cat litter. It sticks to their feet and gets all over.
NOW, with a goat, it still does not absorb but they love to eat it. >? Mine thought it was a snack.