Help me convince "FHU only" friends to try electric only CG

My wife and I are FHU people. We bought a trailer with a bathroom to use it and not have to use the campground bathrooms. If a campground does not have a full hookup site available we look elsewhere. Now I know we can save some water but in general we fill the grey tank in one day. Our black tank is usually 3 or so days. We just like what you get at private campgrounds. Also we do not want to have to run off batteries and almost all state and national parks in our area have no hook ups at all.