I haven't tried using exclusively fleece, but I think there's two things that help with keeping it from causing respiratory problems:
I don't think anyone has mentioned this and it's kind of different, but I was given puppy pads (I think?) when I was a young teen and first menstruating. These things. Anyway, I put them under my fitted sheet but above my mattress, so if I had a nighttime accident and bled onto my bed, I only got blood on the fitted sheet and the puppy pad and not the mattress or anything underneath. I just stashed the box under my bed for storage.
Yep! Right here.
https://www.amazon.com/dp/B00MW8G62E/ref=cm_sw_r_cp_api_glt_fabc_9PSPV3FEXX9W45MBFT9T
They also have reusable/washable ones, which helps with saving money. Either way, just stick them under the fleece blankets/bedding and I’ve found it helps with absorption. Typically when I spot clean their cage I will check the pads and if they’re too soiled I will switch them out. If not I just do it when I clean their entire cage.
I now have a c&c cage but before I had a cage that I ordered off Amazon and the bottom was like a canvas type material. I didn’t want it to hold any smells so I started using the puppy pads and after that, the actual bottom of the cage (under the pads and the blankets) never got wet or stained. Highly recommend!
Probably not what you want to do, but putting two 22x22 next to each other will get you closer to the 40”
I like to use puppy pads! They're reasonably priced (I buy mine from Amazon and disposable (which can be a pro/con depending on how you look at it).
Also, as for fleece, I was actually having a problem with my girls constantly digging under their fleece bedding. So, I wound up sewing custom fleece linings that fold over my C&C cage. It was a day-long project, but so so sooo worth it.
Ohhh, I think I have an idea: I switched puppy pee pads from what the rescue agency gave me (limited amount, I ran out) to something I got from Amazon: https://www.amazon.com/gp/product/B00MW8G62E/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
No idea what type the rescue agency gave me, so maybe it's the scent even though the pads are in the same location?
So when it first happened to me, I was kinda mortified, too, and I didn't have a whole lot of disposable income. So here are some solutions, from cheap through luxury.
Happy exploring!
OMG... really? I buy these and cut them into halves and quarters : https://www.amazon.com/gp/product/B00MW8G62E/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
Would these work? The only issue is they're 34x28, so close but not exact.
https://smile.amazon.com/dp/B00MW8G62E/ref=cm_sw_r_cp_apa_fab_qCJDFbNFXAY5R
I knew a couple who had this problem. They used those training pads for dogs. kind of like: https://www.amazon.com/AmazonBasics-Training-Puppy-Pads-Regular/dp/B00MW8G62E It made clean up way easier.