What's the longest you've ever left water in you canteen and drank it?

This going to sound a little far-fetched, but during Desert Shield/Desert Storm I had lost or at least thought I had lost my canteen, but near the end of our 11 1/2 months in country from Sep '90 - Aug '91, I found it buried in the bottom of my packed duffle that pretty much stayed in our conex for the tour, and I was having to clean everything to be inspected before we could be cleared to leave country, I actually thought I would give it a taste to see if those tablets we had dropped in almost a year ago had actually worked for the purification of the water, the canteen was lighter than when I packed it, I assumed evaporation from time and heat. I took a drink and thought my throat was going to burst open from the disgusting solution I had just put into it, it tasted as if I had drank a combination or burnt motor oil and fermented wine, and through in some salt on top of it.

Lets just say I had a good dose of diarrhea for about a week after that little sig and swallow, never again or since did I ever consider doing anything like that in the rest of my career or since.

Liquid death is the best way I describe the taste after all these years.