Im trying to figure out what to do about this problem, I've had my ac guy out and told him about the problem and he has never heard of dss, so he doesn't know how to fix it. I've found out online that you can coat the coils with something. Can anyone give me some feedback on this? I really need to get this problem taken care off asap!

I've read that the first thing to look for is low spots in ducts, where water collects and gets bacteria and mold (not airborne though, so not a hazard, just obnoxious).

You don't say anything about your unit, where you live, when it's most smelly...