Cotton and any other fabric is a serious risk to any animal's welfare.It can easily cause intestinal blockages,loss of nails or limbs,choking,etc.It should never be used under any circumstances due to how unsafe it is,but that is not limited to just the cotton fluff.Any sort of fabric item is a risk due to how much hamsters can chew
Take everything a pet shop says with a grain of salt.They're hardly ever that knowledgeable when it comes to pet care,and that is hardly their fault,though I've heard of some wonderful pet shop employees who actually know what they're talking about but those are quite rare.They're not there to educate you on proper care,they're salespeople at the end of the day,and nobody can blame them for that
