This high-dose urea cream  is clinically recommended for individuals struggling with dry, wrinkled and rough skin, skin cracks and fissures on the heels, psoriasis, eczema, corns, calluses, and nail fungus. 
At these higher concentrations, urea can work as a moisturizing and keratolytic  agent which descales sent the skin, causing it to shed off dead skin cells and bind water to the skin to provide a hydrating and deep moisturizing feel to the skin. When skin is softened, it aid penetration of other topical skin care products.
It’s also used to treat nail fungal infections. .
 Applying a thick layer of  this topical urea cream on the nails, hand or feet  then wear sock while leaving cream to absorb over night. 
Wake up with a soft and hydrated feet, ready to absorb other topical products including treatment for dark feet.
This is  a moisturizer , apply on hands and feet as needed and it is mostly recommended for use at night as it contains lactic acid which is an AHA .