piss + chlorine will not produce any bad gas end

bleach and ammonia do when mixed do make a deadly gas so you are wrong there the real problem is that with most ppl will smell the gas and get out of the room with only a nasty headache before they pass out and die it is why most restaurants dont carry bleach anymore cause Mexicans that work cleaning would mix to clean the floor and anyone around would get a bad headache i have seen it first hand now if you can immobilize the vic ie hogtie or handcuff and then place a thick trash bag over the head with a soaked ragg with the above mix then duct tape the bag to the neck creating a fairly good seal they should be dead within a 5-10 min window