Yea, I've seen the dual head sponges on ebay for around $2 for 1, and that includes shipping. If you really wanted to make your own, you could get a large sponge from Home Depot. Make sure the sponge is not treated with any chemicals or antibacterial stuff. Get a pvc pipe, cut to length. Cut a small core hole into the sponge a little smaller than pvc pipe. Jam in the pvc pipe and you are good to go. Pretty easy. But you would spend about the same as one of the dual head sponges that are pre maid and work well already.