Propane can be used like alcohol injection...
they spray it into the aircharge just like alcohol. However, I am not all that fimilar with it.
Also I like to use denatured alcohol instead of methanol. While methanol is cheaper, it is more corrosive. denatured alcohol is mostly eythl alcohol (which is pretty much everclear denatured with a bit of methanol.) It is easyier on pumps and lines.