Yes, the MSR Filter shows as working pretty well without the "Purfication" drops. Funny that Katadayn hasn't caught on and added it. Their comparable filter would all have three check marks as well if some bleach was included in the kit.
So, I think I will get some Chlorox in a small dropper bottle and carry with my Katadyn Hiker. Filters the water and couple of drops (I believe it's 4 per quart) will purify it and I am good to go.
Thanks again for posting this up Blast.