I mix Borax laundry detergent w/a bit of cold water in an old shampoo bottle, pour some into a washcloth...the water seeps through, so catch the grains. I then take the washcloth (holding the grains inside) and scrub the edges of my feet (which is where the worms have come out and adhered to my feet).
Be careful not to scrub too hard or your feet will be raw, the first time I did it, my feet itched so bad and the cloth felt sooooo good I scrubbed a little too much.