How to remove smell from hot water?

The hot water in my house coming from a hot water storage cylinder smells of rotten eggs. I know that the property has been left empty for many months before I moved in recently, and the water in the storage cylinder has probably been left stagnant for a long period. I have tried running the hot taps until cold and then repeated this with reheated water for a number of times. This has helped a bit but hasn’t got rid of the smell. I wonder if descaling the cylinder with limescale removing chemicals would get rid of the smell, or will I need to replace the cylinder itself?