Unless they have changed purification tablets used to taste.
Chlorine tablets taste as you would expect them to. Iodine tablets, when you could still get them, were even worse. You can neutralise the taste with Vitamin C powder, but that stops them working, as well, so mustn't be added till the last minute.
Chlorine dioxide tablets (whose chemistry perplexes me) work a lot better and, surprisingly, don't impart any significant taste at all to the water. They are quite expensive, though, and (like all purification tablets) have a shelf life of a year or so,