I've wondered the same thing myself. My tank & pump are on opposite sides of the trailer with 6 or 8 feet between them. When I was done winterizing I redirected the pump back to the fresh water tank hoping the antifreeze would blend with whatever is left in that section of the line. Worked fine last year.
I wonder if turning on the pump with the fresh tank empty will pull whatever is left in the lines out. Probably should've done this before I started the process and not after.
2007 Shamrock F19 hybrid - 2010 (22 nights), 2011 (24 nights), 2012 (11 nights)
2013 Surveyor Select 235RKS - 2012 (6 nights), 2013 (32 nights), 2014 (26 nights), 2015 (37 nights), 2016 (14 nights)