I can not abide the smell of a truly rotten potato. It reminds me of a nightmarishm life-changing experience I had when I was in high school. One whiff and I am retreating into another world!
You will never find a rotten one in my house. When I buy potatoes, I buy the smallest amount possible and either use them all up at once, or count them into zip top baggies and place them in the very front of the pantry on the center shelf so they can't be forgotten.