Moisture remains on the evaporator not the condenser.
there are a number of manufacturers that have added circuitry to the car making the inside blower stay on for various time intervals after the compressor (or car) is shut off.
There are various ways to get disinfectant to the source of your problem. THe very best I have used is sold by Toyota. It is an aerosol that is sprayed into the drain hoses under the car. It goes in and foams all inside the evaporator housing. It lasts for about 20 minutes and then the foam condenses back to a liquid and drains back out. I did it to my wifes ML when it was two years old and the problem has never reappeared (Florida is the worst for such problems). I was a little worried as the car smelled of Ammonia when I drove it home. I asked her about the smell a week later and she had never smelled the Ammonia. I never did again and the new car smell has endured (original owner 1998 ML320 32k miles).
Bosch Master, ASE Master, L1
33 years MB technician