Chlorine Dioxide is still very toxic and ends up as chlorite when used to treat water, which is toxic too and no doubt kills some of your good gut bugs.

Another overlooked option for sanitizing water is sunlight. That takes about 6 hours on a sunny day, so depending on conditions that can be a very doable option too. It doesn't work on overcast days though, so it's not always a good backup plan. But, here again, if you filter your water with charcoal before you set it out in the sun it will sanitize faster than if you didn't.

No, charcoal filtering doesn't "purify" water, but it makes it easier to purify rather you use chlorine or sunlight, and it removes chlorine after it's been treated with it, and that's a very important step in the process that should not be ignored.

I know we've all overlooked this step since we started using chlorine, but we were ignorant. We really didn't know any better.

Here's some info on that...