We all get onions, potatoes and other foods in plastic mesh bags. My grandma used to make pot scrubbers from them. All you need is a plastic mesh bag, crochet hook and cotton yarn.
First cut the ends off of the bag and lay it flat.
Then fold it into a square.
Using a crochet hook and cotton yarn that will fit through the holes in the mesh, crochet a border. Be sure to catch all the ends of the layers of bag.
If you can't crochet, you can thread the yarn on a crewel or embroidery needle and whip stitch the edges. Use coordinating colors; I just used these so they would photograph clearly.
There you go, a tough, hardworking and free pot scrubber. A la my grandma Bosley.