There is appearance of a waxy, lubricant; oily substance called the between the foreskin and the glans of the penis. It consists of natural secretions and shed skin cells. This smegma is usually produced during puberty and provides a natural lubricant between the fore skin and glands.
The foreskin in the child is usually not retractable and is retractable by mid - teenage. Thus in a child while cleaning the penis, the foreskin should never be retracted. Only wash away what ever is external and readily visible.