Sounds like you are a bit confused. Once you winterize with the "pink stuff", you want to keep it that way until you de-winterize. De-winterize will replace the "pink stuff" with fresh water. You will also need to flush the "pink stuff" out of the lines before using any water.
The "pink stuff" will not hurt you if you drink it or it's diluted with fresh water. But your water will not taste right, and it will be foamy.
You should keep your camper completely winterized, including the water heater being drained, until you reach your destination. Then go through the entire process of flushing out all the lines. After flushing all the lines ... THEN open the by-pass on the water heater and fill it.
Just like your fresh water tank, if you get "pink stuff" in your water heater, you will have difficulty flushing it out. There will be traces of it in your water lines for a long time, keeping your water tasting funny and constantly foaming some. Eventually it will flush out with enough use. But keeping it by-passed until the main lines are all flushed out, then opening it to fill it is what you really should do.
A pressurized air tank may be adequate to blow out your lines. But it depends upon how large and how much pressure the tank holds and is.
You should never put "pink stuff" in your fresh water tank. And if you dilute the "pink stuff" with water, it looses it's effectiveness. The object of the "pink stuff" is to *replace* the water so *no* water is in the line. If you add "pink stuff" and then water to your fresh water tank, you might as well just buy a new tank now! The water will freeze.
Keep your fresh water tank empty. The very small amount of water in the tank that remains after draining, will not hurt anything. There's plenty of room for expansion of the ice, unlike a water line that is only 1/2 inch in diameter.
Bottom line, keep it winterized, and de-winterize when you reach your destination. Winterize again when you return home.
