Hmmmmmmmm... Years ago a friend was selling laundry balls that you used instead of detergent. He asked me to give them a try (the old "puppy dog" trick). I told him I'd buy them ONLY if they cleaned my gym socks. I had some white socks I wore all the time, but no matter what I used on them to clean them they were always grubby-looking. I think it was because they weren't all-cotton because I never walk around in my sock feet, and my all-cotton socks never look grubby. ANYWAY - I tossed those socks in with EVERY load of laundry I did for a month and they never looked any different from all the trips through the laundry - even though they were never worn. So from my experience, they didn't work any better than just adding laundry to water and swishing it around would. That's not very scientific, but that my experience.
I do, however, like the non-toxic concept.
~Gingerbread