We use a portable macerator like this one to do the final rinse and flush when we arrive home.
Granted the 3" slinky is faster at the campground, but if it's 500+ miles to home it's a lot easier to do the final clean out with the macerator. We have water and sewer connections in the garage just for this purpose. It also makes life a lot easier when traveling during the cold winter months.
There aren't many if any campgrounds or dump stations open during the winter months within 400 miles of home. It's either use the macerator or leave everything in the tanks and wait for the giant brown pyramid to thaw. Personally I'd rather pump it out before it freezes than wait 3 months for it to thaw.