Pace Arrow

This is a friend's newer rig, Pace says to put about 5 gallons of antifreeze in the main tank and pump it through all the lines, that got to be a pretty dumb way to winterize, but it looks like the only way as there isn't much for bypass valves in the coach, just trying to winterize a better way without filling the main tank with antifreeze, lines have been blown out but still residul water left in lines and the toilet valve, Bc weather does and will freeze that bit of moisture and break that valve, there just got to be a better way. no problem's with my own coach, lots of valves and just draw the antifreeze through the pump and job is done, Thanks for listening, Johnny G1