How did you believe he finished a shed with no shed skin in the cage? It appears that you were going to have a stuck shed regardless of a early soak. I would mist heavy and place a damp towel in the tank for your snake to crawl through. This will moisturize the skin as well as give it something to rub against. I would venture to guess you humidity is to low and would suggest adding damp moss to the hides. This will raise the humidity in the hides and give your snake the humidity it needs without having to keep the whole tank high. If the rock hide in the pic is the only hide you have this idea may not work and with more information about your setup I would be able to better assist you. Maybe a pic of the whole cage.