Well when I hiked 250 miles of the PCT, I used this crazy chemical kit from OMC. You'd stick one tablet in and let it sit in the water for like 20minutes or longer, then you'd spoon in this other stuff that supposedly neutralized the first chemical. Haven't seen it since, but it worked great for me, and I don't remember there baing any aftertaste. Just got jealous sometimes when I'd get to camp, and my filter totin' buddies were drinking cold, fresh water while I had to wait.