Last weekend we made an attempt but were not successful. You see, the RV antifreeze is a noticeable pink color so you can see that it's going through the waterlines (and also so you won't drink it, although the maker swears it's not poison). I think the day we poured it in, there was already a little frozen water in the lines because the pump wouldn't. Pump that is.
But after temperatures rose over the freezing mark we tried again. We poured a gallon of water on the three gallons of pink stuff and turned the pump on while we held our breath. It worked. All spouts produced the foamy pink liquid.
That's the good news. The bad news is that we are probably stuck in the "brix and stix" house until spring. Ugh.