One of the things we have to remember when reading about leprosy in the Bible is that it referred to any skin disorder and not the disease we know as leprosy. Both of the healings in Mark and 2 Kings refer to the healings as being cleansed: Naaman washes himself seven times in the Jordan and the leper is made clean by the touch of Jesus’ hand.
The image of cleansing and water are so connected with baptism in the Christian tradition that it is hard not to see these cleansings as being cleansed of sin and purified. Removal of skin afflictions would have meant one could re-enter the community – the pure, clean community.
Imagine yourself as Naaman washing yourself seven times in the Jordan. What are your sins that need to be washed away? Depict yourself in the water with your sins drifting away in the water. You can do this by writing words that look like they are fading.