Hint: IODINE is by far the most effective disinfectant but care and common sense must be used when iodine is utilized. Iodine absolutely kills 100% of living organisms. It needs very thorough flushing. Use recommended dosage for purifying cloudy drinking water.
#2: Personally I have not found an even close rival to -genuine- vanilla extract for ridding systems of tainted odor or taste. Sometimes it takes a $full$ bottle to dose a tank and lines. After flushing the system it does not leave a vanilla aftertaste. But it really "sweetens" the taste for a long time afterward. Also great for white water fill hoses.