Soak calloused feet in warm water for a few minutes, then apply ointment or medicine prescribed by a doctor and wrap them in gauze all night. After the calluses are softened, gently scrape off the dead skin with a knife, and then apply deep moisturizing hand cream. In addition, if there is no ointment, you can wash your hands or feet with vinegar every night, and then apply the vinegar to the calluses with a cotton swab. If you insist on using it every day, it will have a significant effect after one month.