High concentration ClO2 solutions goes through some plastic like a hot knife through warm butter... [smile icon]
Keep in mind that agitation activates sodium chlorite solutions. I think you would be better off using water in your water pik, and rinsing with a sodium chlorite solution afterward. This also follows standard operating procedures for using these chemicals. You clean first, then disinfect.
The studies I have reviewed indicate that adding a little sodium chlorite to tooth paste is not as effective as brushing your teeth, then rinsing with a sodium chlorite solution afterward. I have also noticed this when adding sodium chlorite to soap for a mild disinfecting wash. It seems to be much more effective to wash first, then disinfect.
It may be a problem of degrees. If you have very few problems with oral hygiene, the toothpaste with the sodium chlorite may be all that is needed. However, if your mouth tends to build up deposits, the stronger mouthwash solution is needed.