I did wart remover 17% salicylic acid.
Applied a thick layer onto the dark areas (which was pretty much my whole shaft)
It will turn white. Then I let it stay on for 10 minutes. It burns like hell. ( I may do a 12 minute for my final peel)
After the 10 minutes I applied baking soda to neutralize the acid, and cold water. Thoroughly.
You will end up peeling off the white left over wart remover, and I believe some of what you are peeling off is dead skin.
That day, you will not notice much.
By day 3, everywhere you applied the acid—the skin will turn very dark.
Day 4, some minor peeling.
Day 5-7 a lot of peeling, until all old dead skin is gone.
Lube/lotion your shaft multiple times daily.
I learned all this, from information from another thread that was already on thunders. Did it myself and it worked.