While water treated with iodine and KMnO4 would be bacteriologically safe, it would not be considered sterile. Furthermore, impurities in the KMnO4 and iodine as well as the chemicals themselves alter the pH (acidity / alkalinity ) of the water restricting its use somewhat in a situation where you need sterile water ( i.e. wound irrigation or eye irrigation especially )<br>All that being said, iodine and KMnO4 in water is better than non sterile water. And non sterile water may sometimes be better than no water at all.