We use cotton to knit them with. Its about all that really works. I found the tighter you knit them the longer they last. We also use colors that can be bleached. That way they don't fade so badly so fast. When they start to come apart, I sew the loose ends back in & put them in a bag to use to clean chicken water's & such.
Cleaning Eggs?
Can you crochet them? When I learn how to maybe i should start on that since I am thinking it would be easy..
Here's a link for crocheted dishcloths. I don't know how easy they might be, it's been many years since I crocheted.
http://crafts.lovetoknow.com/wiki/Free_Crochet_Dishcloth_Patterns
That looks simple enough Loreen, humm I think I will try it..