I would run the 50 / 50 mix . Water is capable of pulling little over 2kj of energy Which is quite abit more than methanol is capable of. Running the nozzle pre blower will cause the liquid to help seal the rotor. Once its thur thats when its goign to really start cooling, same as running post blower. The reason for running the mix is usually the water will evaporte before it hits the cylinders and then you are left with the methanol.