From the company -
Woolzies are 100% pure new zealand wool dryer balls that do everything that conventional fabric softeners do plus they reduce drying time by 25%. They are money back guaranteed to last for at least 1,000 loads! Woolzies have no chemicals at all and are also hypoallergenic so are safe even for people with wool sensitivities.
I've been using these for about a month, and I think they're a terrific alternative to dryer sheets. The company recommends using essential oils to add scent - I haven't tried this yet b/c it involves adding the scented ball to the load on low/no heat. I can barely remember to move clothes from the washer to dryer, much less remember which ball to throw in w/o heat. The only downside that I've found so far is that you'll definitely hear clunking while the dryer is going. Other than that? My hippie-laundry self wholeheartedly recommends!
I received the product mentioned above for free using Tomoson.com. Regardless, I only recommend products or services I use personally and believe will be good for my readers.