Hey gang. I just got 2 air con units (one window, one split) replaced by DSC. I wanted to take care of them but the salesguy said that I only need to clean the filters. He said not to clean the other stuff since the chemicals they use ruin the machine. He went on to state that each time his clients get their air cons cleaned they end up having problems within a year. I have been told by many that you should get each unit professionally cleaned once a year but now i'm a bit hesitant. What do you guys think? Are there companies that use non-corrosive chemicals? Should I just learn to do it myself?