I have never been able to eliminate the odor from our hot water tank. Some water just smells worse than other when heated.
There is no anode rod but I have flushed and drained often enough to know that does not help.
About the only thing that did help was continuous usage. When we were on an extended vacation and using the hot water a lot, there was less odor.
I also found that the heater get the water very hot very quick so I usually shut it down after about a half hour. The waters stays hot all day and is not being re-cooked so to speak. When it is cooled or used up it turn it on again for a bit. There is no temp adjust on our gas/electric model.
Good luck