Water/**** does work, but as one of our members found out the hard way, more is not better. Trav and E-1 had water/**** on the last engine that Trav put in E-1 (Yes there was more than one, 3 or 4 total I think, one - cavitation, one - threw a rod/s, and at least one that was "killed" with water/****. With the nozzle he used, you could have mounted it to the cowl and used it as a window washer..... the last day for that engine was at a rally, and he was playing with it, and went through something like 15 GALLONS of washer fluid in an HOUR..... basically hydrolocking the engine on each compression stroke, cracked all 8 pistons and started to shove the wrist pin toward the crown of the piston. This was an extreme case, but be warned.... it could cost you and engine.
Darrin has been running propane in Big Ed for years, with different powerplants.... and has success with it. He just posted about it in a thread about propane here in the last few weeks.....