Has anyone put a bypass valve in line with the demand pump to be able to more easily winterize the coach.  I took my unit into a RV dealer and it was almost $200 to get it winterized. The technician said he had to disconnect the lines on backside of pump which I can understand and it was difficult also with washer and a fridge with icemaker .

Had the unit have some type of valve with a tube  to be able to put in antifreeze bottle that would eliminate a lot of hassle.  Any suggestions? I have had a number of camper, 5th wheels and never really had that much of an issue winterizing a unit.