That's my experience also.... and the guy at WM recommended it years ago..Probably because they make more money on the other stuff Joe!
I've used the reinforced tygon tubing for a couple of decades now with no failures. Sanitation hose is good stuff for it's intended use, the movement of waste and not allowing odors to penetrate.
So... who could have predicted this subject to generate so much discussion... not me."Drain hoses
Drainage hose for cockpit, sink or shower, needs to be flexible with strong walls and resistance against kinks and abrasions, but since they are under positive pressure, they may not have a helical wire.
Maybe one is rated on non-permeablity of odor and the other is rated on resistance to puncture, burst or whatever else the criteria for below waterline use is. There are head installations that have no thru-hull at all. The manufacturer doesn't know the installation specifics.1. From the chart you provided, drain line below water line is rated good while toilet water inlet is rated excellent. Can't see any major difference in basic function as both are below the waterline.
try 14 years.......I went all day not worrying about my tygon tubing. Now, if I could just find a piece of white tyvek without buying a $100 roll.....