I have a 34 foot Mh and I can winterize it with 1 & 1/2 gallon. I never pour it in the fresh water tank and always by pass the H/W heater. If the antifreeze freezes it will not expand. Did it burst the bottle or swell it? There may be a shelf life on RV antifreeze but I dont know. As many rvs that are in the north and use it I am sure if it did not do as advertised the lawyers would be having a ball. I have seen it slush even here in Alabama in the jug. There is plenty room in the fresh tank for expansion so I dont think there is a need to put it there. I have never heard of dealers doing this. Yes I do drain the tank and also the H/W tank. All JMO. If there is no damage to the RV why worry?