It could smell like dog-poop, old cheese, ammonia
, a burning smell
, etc. The smell
comes on, often, as a result of a cold or sinus infection. Some, not all, of these smells are caused by an anaerobic bacteria thriving in the upper sinuses, and I was able to remove mine with a Flip-Turn Sinus Flush, and many other people have had success with it as well. I have already mentioned this in the earlier part of this journal, with a solution.