These wool balls are taken from 100% wool sweaters.
We carefully unravelled the sweaters (don't flame me, my lovely knitter friends!) and then wound a small, tight core.
I fulled the cores, then wrapped the core with more yarn, until the wool balls are just a tad smaller than a tennis ball. The balls were then fulled again, through several hot washes, until they are partially felted.
We tested a batch of dryer balls in our own laundry, and I have to say that they are effective in reducing static! They are the most effective with cotton and cotton blend fabrics, and the least effective on 100% polyester items. (But then again, commercial dryer sheets aren't that effective on polyester, either.) We used one ball in our laundry, and had positive results. Some people use two or more, and claim even better static reduction.
Our product tester, one of my sweet customers, gave the dryer ball's static reduction properties a 9 out of a possible 10 (1 being no noticeable static reduction, and 10 being the best static zapper ever.) Not bad! She was so pleased with the dryer balls, that she said she would recommend them to friends, and buy more for her own family. (Thanks, Sara!)
Oh -- and my sachets were on the Front Page tonight!
(Thanks, vintagedchic, for including my sachets in your lovely treasury!)