If you were to do a truly "water only fast" you would fully understand what can be achievied from dong so.
Its just one of those things you have to experience to really understand.
There is no "cheating" or shortcuts to this end.
It usually takes determination and goal setting to get there. And you will find a good percentage of people unwilling to muster up the determination needed or to really set a goal.
Hence, the alternative is "cheating" and shortcuts.