Stinky smell from air conditioner in 06 volvo s40 2.4i

[Danaca]

My ac does work but eventually it'll stop working and begin to blow stinky air. I've been told that there is mold in my plugs and that I should get them cleaned. This is said to be a simple process. However, I can't locate the plug to actually unclog it. Someone said that I can stick a wire up the plug and unclog it. How can I fix this?