We use bleach to disinfectant the system after the rig has been sitting for awhile. Add one cup of bleach, fill the tank all the way, let it sit for awhile, drain, fill and drain.
If you want to disinfect the lines OK by running the bleach water through the lines, but be sure to run fresh water through all the lines and dump the water in the hot water heater. Bleach is no friend of rubber gaskets. And does not taste good either.
Now add chlorine dioxide and fill the tank. Add another table spoon every time you refill.
It's safe, you are already ingesting it as it's the most commonly used chemical to disinfectant, for instance, food prep counters and it's used in city water systems.
We always run out of the tank. We never hook up to city water. That keeps the tanks filled with clean water.
Here is a source for the brand name Purogene which is nothing more than 2% Chlorine Dioxide.