ClearZal® BAC has a unique delivery system which ensures that the formulation directly reaches the target area. Studies show that by first debriding/filing the free edge of the target nail with the nail file provided and using ClearZal® BAC twice daily morning and night, will achieve optimal results. Studies show that by first debriding/filing the free edge of the target nail with the nail file provided and using ClearZal® BAC twice daily morning and night, will achieve optimal results. Directions: File the free edge and top of the nail. Clean the nail and surrounding skin and dry thoroughly. Apply the solution under the free edge of the nail and surrounding skin. Allow to dry or massage into the skin. Use twice daily around the entire nail and under the free edge. Remember to apply before you put on your shoes and socks and when you take them off.