I blow out the water system first with air after I drain the water tank and hot water tank, put it in the by-pass mode on the water distribution valve panel. I also remove the water filter and install the filter replacement insert for the drinking water and ice maker. I also remove the water lines for the icemaker and shut the valve off for it.
Then I also use RV antifreeze pump thru the system with the hose that I installed in the into line from the tank to the pump. I just had to turn two valves that I installed just for this purpose. I make sure that the antifreeze is pumped thru all the lines including the ones for the supply to the icemaker (but not into the icemaker valve) and cycle the washing machine as recommended by the manufacturer.
As far as the anti-freeze taste after flushing all the lines with water, I have never had such a taste. But I do flush with lots of water. I NEVER put any antifreeze in the fresh water tank, I just make sure it is drained as much as possible.
I know that to some that I go a little overboard doing both, but I have never (knock on wood) had a leak in any of our RV's in 18 years using this procedure. In our northern winters, I just have a warm fuzzy feeling doing it my way.
Another thing I found out works real well is we head to Florida right after Christmas, never had a frozen water line there in the past four years.