[nutron]

Well firstly, there is no such thing as suction. The absense or reduction in pressure in the intake line allows the pressure in the line from the water tank to disipate into the intake. The reduction in pressure in the vessle containging the liquid if sufficient could cause the liquid to boil at a much lower temperature, i.e. what ever temperature it is outside. In practice you would not get sufficient vacuum in the vessle to cause water to boil. Both water and methanol will evapourate at room temperatures normally and with that method they will evapourate faster but the tiny amounts of vapour being inhailed by the engine would be insignificant.

So no, it's rubbish. Using just plain water injection though can decrease emissions output, increase torque and improve fuel economy.