I agreed with your sentiment, but can't agree with your math. Stringing together too many nines or zeroes after a decimal point for reality is a common bit of hyperbole, but the parenthetical statement implies that you were serious.
If something doesn't apply to 99% of x, then it does apply to 1% or 1 in 100. 99.9% would apply to 1 in a thousand and so on. Your number 99.9999999% means it would apply to 1 in a billion (thousand million for UK readers) divers. I think the total number of scuba divers in history is under a tenth of this number. Meaning we might have to wait for several centuries to find a situation where the procedures would be useful.
Sorry, pet peeve. Carry on.