The information in the above post is not correct. Adding low ppm sodium chlorite directly into water will not harm you, and it is something that Jim Humble himself has done and continues to do under certain circumstances (ie. water purification).
I have been using unactivated sodium chlorite in water for 4 years now, and I know many hundreds of others who have done so as well. This protocol (unactivated NaClO2) has been around for about 40 - 50 years, and there has NEVER been a reported problem. There have been many, many testimonials, including my own, about its efficacy.
Dr. Robert Young uses this as part of his protocol, and you can go to his site, phmiracleliving.org to read a ton of testimonials about this particular usage of NaClO2.
Jim Humble's protocol (MMS) uses pre-activation and a higher concentration, and THAT is relatively new. If anything, it is that higher ppm and the pre-activation which generate the higher ppm chlorine dioxide in the body which create problems for many people. Generally not because of the toxicity of the NaClO2 or ClO2, but due to the toxicity of the pathogens and their debris as they are killed off.