Stinking is a word that can be used to describe anything from an unpleasant odor, such as body sweat or vaginal discharge (even when it doesn’t smell), up to something more extreme like a dead animal smells.
Mildly fetid would refer more specifically just one instance in which there are hints of badness but not enough for your average person’s nose; these words often carry nuances about their subject matter- whether this topic has intrigue or repellence, you’ll need some imagination!