Look for Aspen shavings - they are sold in bulk and are extremely cheap. You can even use shredded newspaper or scrap fabrics you have lying around - ANYTHING is going to be better than the pine. Please, stop using it. It will save you from heartbreak and expensive vet bills in the future.
Yes, I know it is sold for rats, and it is WRONG. Just like McDonalds sells food for humans... it doesn't mean it's good for us! Pine is still marketed for small animals because it is CHEAP and people who don't know any better will buy it, not knowing it is toxic and will make their pets sick.
No one is trying to accuse you of being wrong, and I'm not trying to discount your mom of her vet tech status, but the toxicity of softwoods is a VERY well known issue in both humans and small pets. We just want what's best for Russel and you have to understand that this isn't personal - we are trying to help educate you to make healthier decisions that will help him live as long and as illness free as possible. If for whatever reason you INSIST on using pine, now you are at least aware of the significant health issues from it and will have to live knowing that if he ever suddenly dies or comes down with significant respiratory failure it may have been your fault for not switching beddings. If you are okay with that, by all means continue.