I sanitize mine once a year in the spring. I do not drink from it but, I use it for everything else.
I've never gotten sick, or had the diarrhea, after, or during, a camping trip.
I reuse my bottled water bottles by refilling them from my home water system. I drink from that on trips. Mostly because I keep them in the fridge and I like cold water.
When the water in my water bottles starts to taste funny (kinda a moldy taste) I thrown them away and get a new one.
I read a article in Popular Science Magazine recently that described it best in one sentence.
" Hygiene is good, Sanitation is not."
By over sanitizing our environment we are making ourselves sicker.
I also eat food cooked over the campfire on my (slightly) dirty cooking grate. I rarely get sick and only go to the doctor once a year for my blood work. I've never been to the emergency room in my life. I'm 52 years old.