This is a common and efficient strategy when it comes to clearing up bad sheds and creating an better appetite. However it should be carried out with extreme care, and supervised during the entire procedure.
Recently, a member from this forum lost a Ball Python when using this strategy. Ball Pythons are not aquatic species, and rarely choose to soak their bodies. Being trapped inside a container with water for a period of them can cause them to panic, and possibly drown themselves.
Supervision is required through the entire procedure; even if the snake seems fine when it was first put in, it might panic later on. Also, extreme care is required; in terms of temperature, if the water is too hot, it will harm the snake physically and psychologically. When it comes to the amount of water; large amounts can be dangerous. Small amounts of water can be just as effective, as the hight humidity of the container also helps with the shed. Lastly, a plastic container filled with water can be very slippery for a snake. A wet towel or paper towels can provide the snake with something to hold onto, and reduce stress.
Every Ball Python may react to this strategy differently, thus not every snake can tolerate it.