The reason it is put on the compressor side is so it atomises better. The problem is it wears your blades out over a period of time.
When using methonol you need to be very careful of hydro lock as it is a very dry type of liquid, no lubrication properties what so ever. A way to get around this is to spray some WD40 into the methonlol/water reservoir.
Using methonol is illegal for this purpose as it is a carcinogenic, but ethonol can be used in its replacement.