Scale rot is caused by high humidity, dirty cages, and cold, damp conditions. When its high humidity the scale rot will occur on the dorsal surface of the snake. With the other 2 causes it will affect the belly. Occasionally blisters of clear fluid can occur. It can be caused when a snake is constantly laying on a cold enclosure floor, with its heat coming soley from above. depending on the severity, scale rot causes the scales to die and turn into big scabs which peel off, leaving exposed skin. Scales are not known to regenerate but i have seen healthy scales surrounding the exposed skin change shape over time and grow over the wound. In any case, severe scars will always remain.
To fix the problem get the snake in a warm, clean and dry cage. Have the snake on newspaper, its the only substrate that wont irritate its scale rot sores. allow any scabs to peel off by themselves and expect the snake to go throw a couple of sheds in succession. I dont think any medication, ointments or baths will help that much. Snakes themselves are great healers.