In alchemy consciousness is seen as a force that can mold reality to a large degree by combining the basic principles of mind body and soul, or salt spirit and mercury (i prefer to think of things as mind body soul as it's easier for my brain). When all of these components are combined with the force of consciousness a system is created between the three realms to where when enough usage, understanding, and effort is applied, it is said to actually change reality or conscious reality. Thus the philosophers stone or elixer of life is not one recipie set in stone but it based upon the mindset of the alchemist and how they relate to their everyday world. Another way to view the mind body and soul connection is to view it as observation creation and evolution.

So with water, most presently view water as a drink and not necessarily much more, but what if when drinking water one viewed water as fuel and said to themselves while drinking water that this is fuel for my body, thus changing their perspective on waters properties? The way i like to think of this is that water is H2O, to where i look at the hydrogen and think of how there was talk about cars running off of hydrogen and even water i think, which connects a stronger form of truth to the concept that water could be seen as fuel. Then when drinking the water what if one feels it go through their body as fuel and then feels energized from it, like a feeling of satisfaction? With enough time this system should become real. Id have the observation of the body of water not as a beverage but as a fuel, id have the creation of the feeling of fuel inside of my body energizing my body, the mind part, and then i'd have to wait for the evolution of this belief to become solid enough in my mind to where it becomes real or a part of my souls makeup. 

This seems possible but i'd imagine the level of subjectivity that the mind would have to get to to be able to make this actual reality for the alchemists would be extreme. This points to why most alchemists or other mystical folk were all hermit like. In society now days this way of thinking subjectivley would be viewed as a mental illness rather than a gift or discovered ability of great magnitude. One would have to be in a state of right brain creator mode more than left linear mode, like always having elevated psychosis chemicals in the brain.

Anyway i'd say that with enough practice one could place mind over matter and exist off of water alone. Correlate the truth light and concentrate the truth light into one solid beam and then intensify the light of truth until the belief is solidified. I'll keep practicing and let you know :)