You need to provide proper humidity and stop soaking this animal, it is stressful and soaking prior to a shed will actually not be beneficial quite in the contrary.
If there is an issue (after the shed not before) use a warm damp towel to get rid of any left over shed.
Also avoid any oily substance has it will loosen up the scales.
Again the key is proper humidity.
Finally shed is related to growth and growth is related to food intake so if you feed him right he should shed about once a month at that age, the key here is proper feeding.