first time sanitize fresh water tanks

About to sanitize my tanks for the first time (we haven’t drunk the water from the tanks, we just use for cleaning and bathing and so on,, but we are about to go on a long trip with many dry days so we’ll need the water for cooking and drinking).

I understand the basic principles - fill with properly diluted bleach solution, let sit, run through all the faucets and fixtures, fill with fresh water, drain through fixtures, repeat until no bleach smell — but have some questions about the details.

1. What do I do about the water heater? Do I turn on the electric and propane water heater switches to make sure any bleach water is cycling through those as well? How long do I let those run to ensure proper sanitation? Do I need to drain that first somehow?

2. Is it necessary to ‘drive around’ with full bleachy tanks to ensure bleach solution is splashing up and coating all the surfaces?

3. When filling the tank, do I truly fill the fresh water inlet until it is overflowing (as I’ve read)? Previously i’ve read not to do that to avoid damaging the plumbing.

I have pool liquid chlorine which is stronger than regular household bleach so I will use the correct amount of active ingredient. when I mix my solution.

thank you