Several hundred posts ago, there was a request on how to fix a smelly A/C. There is a product called DWD2 that may fix this problem. I've seen it advertised in magazines (C&D?) and was tested on MotorWeek (PBS) a long time ago. I believe they got good results. It doesn't hide the odor but removes it by cleaning the evaporator system. I posted the URL for more info.