I have one bun who would eat the Carefresh out of his box and, because he has a sensitive tummy, it would make his cecals messy and I’d have to give him butt baths. I was actually very lucky that he never got a blockage from ingesting this product. It is a great litter companion for non-munching bunnies, but the packaging does say not to allow them to eat quantities for that very reason.
I can’t use it for my lop because it’s just dusty enough to aggravate his sinuses. It’s a shame because it’s a nice, absorbent litter.
Perhaps you could switch to a different type of litter that Oreo doesn’t find as tasty? I use Yesterday’s News and if they soil it quickly I spread some hay on the top sometimes until I can scoop out the wet spots. Or there are always the safer wood shaving options, like aspen? (I think that’s the one to use…just not pine shavings, those are toxic to bunnies.) The only pine litter that bunnies can use is called Feline Pine. It is specially treated.
Perhaps she is looking for a little more fiber in her diet? I feed orchard grass too, but notice that once in awhile my buns need something a bit more tough to sink their teeth into, so I always keep some timothy and oat around for those days.
I’ve also cut out pellets. I find my bunnies have a lot less GI stasis episodes for giving those up. Every bun is different though.