I learned recently that these scrubbers are made from acrylic yarn. I found that out by trial and error, but there was an article and a pattern written about these useful little things in the latest issue of Craft magazine. According to the article, (what I remember.. I read it yesterday at the bookstore) these qualify as eco-crafts because they are effective without the use of soaps or cleaning chemicals. Also, they are durable and reuseable.
Here are the ones I've made recently:
In this book there are about as many knit patterns as crochet:
The ones on the right below appear to have a soft sponge inside. I've been wanting to learn this kind of knitting:
Here are knit houses and funny crocheted dusting girls:
Here are hears and stars:
This book also has a bottle scrubber, some cute animal faces, simple fruits, and a colorful crocheted mitten scrubber and a glove scrubber.
Finally... This is the advertisement at the end of the booklet for the yarn they are using. I can't read any of this, but maybe this is useful to someone! This same ad is in all of my magic scrubber pattern books.
Note: I edited this post from an earlier version where I'd included a photo of one of the patterns. I've since had a crisis of conscience about copyright and have deleted that photo.