For extremely callused, dry feet, use the Coarse Callus Grater. Gently move the blade side across callused areas with clean, dry feet. As necessary, apply more pressure until you reach a comfortable level. Use prudence when using. Fine Foot File: Gets rid of dry skin and small calluses on feet. Suitable for dry or wet use. To get softer-looking feet, scrub away at the dry areas with light pressure.