I can't figure out why the "aftertaste" is an issue with the anit freeze. I sanitize my fresh water tank and lines regularly anyway. The anti freeze aftertaste is the least of my worries. I worry much more about what's "growing" in the water lines during storage.
For me the anit freeze is cheap & easy insurance against a bad suprise come spring. I used to just drain everything real well in my old trailer, worked great for a few years then one spring I had water lines broken in 3 different places
Not fun. I've been using anti freeze ever since.
Last fall I was talking to a service tech at a local independent RV service shop about winterizing and asked him about blowing out the lines. He told me that they will not winterize a unit for a customer with out using anti freeze.
Anyway just my .20 (no that's not a typo, that was just too long winded for just .02)