I recommend paper based bedding, hemp bedding and coco soil. If you’re looking for something soft that isn’t loose you could use fleece. Here’s some more info on rat bedding: www.smallpetjournal.com/bedding-for-pet-rats/
Sometime in 2022, I’ll be able to move my hamster into my bearded dragon’s old enclosure so I can give her more enrichment (The current enclosure has a ridiculous amount of bedding, but I can’t fit much in the top). I’ve also started to switch my animals to natural soil bedding so I’m looking forward to sending you a pic of the final product. You’re my favourite rodent RU-vidr by far!