I have both left it for dumping later and ran bathroom lavatory (drains to black tank) to get 1/2 to 2/3 full. We have a sewer clean out at home I can dump/rinse tanks into but it requires a little jockeying around yard to get MH positioned. I'd like to get a macerator or sewer solution to make dumping at home easier.
We also will use MH facilities at home when working out in yard or shop. A few trips I've actually swung around by dump station upon arriving at campground to dump before setting up site.