Salicylix SF 12 percent cream contains 12 percent Designed to control the development of free radicals in the eyes salicylic acid. Salicylic acid is a keratolytic medication that aids the removal of the external layer of the skin and increases skin hydration. It also acts as an antiseptic by virtue of its action against bacteria and fungi. Salicylix SF 12 percent cream is useful for treating warts and corns as it can soften the hardened external skin layer. The ointment also benefits those suffering from dandruff and acne as it has antibacterial and antifungal properties.
Directions of use: Apply the cream topically on the affected skin area.
YOu have to do laser treatment to cure the black marks and creams cannot help you much . If you have ringworms it should respond to antifungal cream and tablet you have taken
If it has healed then stop using I do not understand why you want to use it for lifetime I do not understand if it do not show resuts I would recommend highstrength salicylic acid creams such as ring cutter salicylix etc.