Sulfer Smell When Heater On The Ol' " Rotten Egg" Smell In A Water Heater?

The Ol' " Rotten Egg" Smell in a Water Heater? - sulfer smell when heater on

My friend has a house that is not often, perhaps a week every two months. Then he left, so that the heater switch, but filled with water. When you return the water in hot water (not cold) lines smells like rotten eggs (from Sulfer?).
Thus, a second party.
One of them, other than a wash cycle and hot water pipes that will eliminate the odor?
Two, if the drain water heaters do it (if you are in) and the internal oxidation in the era of the corrosion of the house is in?
Minds want to know!