I'll tell ya something I did once when some plugged humidifier ports blew holes in a large evaporator. Changing it out was dificult in a timely way so I reasoned menthol alcohol would displace the moisture. I isolated the evaporator and blew 2 gallons of alcohol with nitrogen. No particular fire problem in this case but you still need a whole lot of percausions. The alcohol was blown througe the evap and washed down with water as it came out the other side. Nitrogen was blown through until the alcohol was evaporated. After that deep vacumms and purges. I was lucky as this happened in the winter and the compressor never ran. Chemically I don't think alcohol should be in a chorline based system so you need to be sure it's all out of there but the system continued to run for years after that. Sometimes you win.