Those who roll their own cigarettes: Can you recommend a natural filter?

Those of you who know I quit smoking, settle down.. this question isn’t for me. I’m done with that particular evil weed. :P

I happen to care about someone who rolls their own and does not use filters. The reason given is trying to avoid waste and pollution, so a cotton filter or something made of all natural/biodegradable material would be great.

I was going to just buy something and give it a shot, but reading the reviews for some raw cotton filters, it occurred to me there may be issues with functionality.

Just wondering if any jellies roll their own smokes and can maybe recommend something to protect some pretty wonderful lungs?