This is a loaded question..City water is treated with chlorine therefor when put into your RV tank,it is already treated,right..
I have only had one RV that needed special treatment of the water tank..I did as advised earlier on this thread..I also do the bleach washout when I take an water bladder or barrel before I ad the water I will be drinking which is already treated..
My currant TC holds water in all the months it is not freezing out and I flush it a couple times a month with fresh "City" water that has been treated..No issues or have I ever had water tank issues doing it this way...
As to which lines are cleaner,house or RV..I have my doubts now since 3 of the 5 wells that feed our city went down and read all the mumbo jumbo the water police had to say about water lines in your home and the sometimes oops to what gets fed to your house...Makesme want go get my own from a creek and run it through my Sawyer water filter and then use the Steripen on that..
I guess some have the, what we don't know about our water won't hurt us,attitude......