The slightly acidic nature of apple cider vinegar helps breaks down tough foot skin, including corns, heel fissures and calluses. You can either soak your feet in a mixture of one part apple cider vinegar and two parts warm water for half an hour to help break down the tough skin, or you can apply it directly onto tough patches of skin. To do the latter, soak a cotton ball in pure ACV, and apply it to the callus with a bandage or tape, being sure not to let the cotton ball touch the surrounding skin, as the acid can be quite irritating. Leave on overnight and then exfoliate the area with a pumice stone in the morning.