[ClumsyPianist]

I'm not sure which part of the box you're talking about (the box or the cottony thing), so I'm just going to address both.

Is the box plastic? Is your hamster a chewer? Probably not the best idea then. If she's not a chewer you could try it but supervise it for a while, and remove it as soon as you notice your pet is chewing on it.

As for the cottony material, I'm really not sure I'd put that in my hamster's cage. You've got this thing called fluffy bedding and that is one of the biggest nightmares for hamsters as the threads loosen and get stuck around their paws, or can get stuck to their cheek pouches if they pouch it. If you're thinking of using it for nesting material, I'd just switch to toilet paper, which is totally safe (and digestible). I'm not sure what it's made of, but I wouldn't trust my hamster with it.

Ultimately you're the owner and you've got to make the shots. You could try it, but I don't think I would because I don't know what it's made of. You might however. Check if hamsters can have whatever the material is and then make a decision. ^-^