Earlier quoted context omitted.
109 cases in a little over 40 years.. yeah, this is more of a freak occurrence. also, the article says they never tested the water, so this idea of the neti pot is just a guess to begin with.
There must have been something else involved. Should we not swim in pools, rivers or lakes, or submerge ourselves in hot tubs? Netis are part of Ayurvedic medicine in India since long before people dreamed of personal immortality. Remember when people worked outside all summer without worrying about excess UV? Maybe we're overthinking this stuff, we Chicken Little emulators.
Perhaps we're not overthinking it. Maybe there are complex processes that we don't yet understand.