I too went the distilled water flush route, multiple times. Final Charge coolant, in 50/50 mix. In hindsight, I should have added a gallon or two of 100% Final Charge too, as I'm sure I had a few gallons of distilled water remaining after flushing and draining it.
I'm going to follow Spike45's suggestion, and have it tested at my next major service. If it is a bit too diluted, I'll drain a some off and add the 100% Final Charge to bring it to the proper mix.
Also be sure you go to the dummy water filter, non SCA, when doing this change.
My engine temp is running cooler after this change over. (Due to age, I also had all water related hoses replaced, and new thermostat. Figured be good for another 10 years on my hoses, as our 2004 model was built in 2003. Rather due it on my schedule and location, then on the side of the road!)
Best of luck,
Roo II is our 04 Country Coach Allure 40'
OnDRoad for The JRNY! Enjoy life...