Ever been too hot to trot? How about too hot with the trots? For every one of us who has experienced the Hershey squirts at the most inopportune moment - and really, when it comes to peeing out your bunghole, every moment is inopportune - MSR has a solution. Literally.
SweetWater Purifier Solution is nothing more than sodium hypochlorite - common household bleach to the rest of us - in water. Sure, you could do it yourself, but they know you're too lazy, so they give you a whopping 2oz bottle, which is enough to treat 80 gallons of water. An eyedrop sized bottle that only treats 40 gallons would have been sufficient, but since most of the cost of this product is undoubtedly in the packaging you still would have paid $9 for it.
Still, if you're wanting convenience here it is. The taste is tolerable, and it does what it says: just add five drops per liter of filtered water and wait five minutes and presto, virus be gone. Ignore the "only use with MSR filters" part. Chlorine is chlorine.