Yeah, I thought about getting one of those 'kettle' things you pour salt water up your nose with (you know, like the one seen on Oprah). My mom keeps telling me to try it. I probably will soon, just pouring things up my nose weirds me out, LOL.
The coworker could have developed some sort of stomach problem. Certain stomach problems can cause bad breath. I heard that Clark Gable was said to have a stomach problem that caused horrid breath.