It's been my feeling that if you use chlorine dioxide you should filter the water afterwards and I once recommended that using an activated charcoal filter would remove the chlorine. There was some discussion here on that, and the general consensus, as I recall, was that it would not remove it.
That's sort stuck with me because I know it removes the taste of chlorine and after reading about what happened to OM with her Sawyer Squeeze locking up I started thinking about this some more.
So I started looking today for what an activated charcoal filter actually does removes that tastes like chlorine. From what I found, it actually does remove chlorine pretty good, there is a time factor involved though. The longer the water is in contact with the activated charcoal the better it works. Here's what I've been reading: www.ianrpubs.unl.edu 1 www.ianrpubs.unl.edu 2 www1.agric.gov.ab.ca
So, based on that I think pretreating with chlorine dioxide and then using an activated charcoal filter is probably a pretty safe, inexpensive, and lightweight method to treat water for our purposes. But more to the point is that even if you carry a filter this makes a good back-up system. Just a few tablets of chlorine dioxide and one of these Dollar Store lightweight collapsable bottles with an inexpensive Britta activated charcoal filter inside them is cheap and light, and it could save a trip:
This also works great to pre-filter and boil water. Boiling water is really all you need, but this way sure beats nasty tasting water that crunches between your teeth