What kind of padding should I use for my dog's dog house?

I have a dogloo for my Golden Retriever and every padding I've put in it for him to sleep on, he has chewed up. I even put the supposedly non-chewable pad and it was gone in a few days. I spent about $60 on that too! I've tried carpet, but that's proven to be a health hazard. He not only chews on it, but it also gets stuck in this throat. It's getting cold now, so I'm out of ideas.