I think it would be a bad idea because water pits the top of your clinder wall and if its was ice cold it looks like it would be worse if you don't have to because water/meth is just untime fuel
First of all.... it's going to be steam, so in terms of what the cylinder will see, the temperature of the injected water is irrelevant.
Secondly, I think you're the first instance of the word "meth" in the entire thread.
I assume the guy is running straight water, or hopefully water with some water-soluble oil in it. No methanol.