Forget using a hose through the bathroom window, this is the solution!
I initially bought the rinser stick that you attach to your hose and put through the bathroom window and stick down the camper toilet to clean it. what a pain! plus it's a gross feeling to pull it back out dripping to remove it. i did this at home after a trip because it took so long to do, plus i didn't want to use potable hose lines at campgrounds to rinse the black tank with! i'd rinse at home, but then i had the problem of a little sewage water to drain once rinsed...what to do with it? buckets to the house toilet. i bought this hoping it would be more sanitary and convenient. yes it is! it was a bit more involved installing it myself as i have an insulated under carriage on my trailer as well as an aluminum rock guard. so getting to my tank at all took more work, but once installed it's well worth the afternoon spent upsidown in my driveway! let my calking dry overnight to be sure it was sealed. it made a big noise when i tested it, which surprised me, but then i realized that was normal. i had to do some doctoring with the hose, since the one it comes with was about 20" too short for my tank. i installed it on the opposite end from the tank outlet like recomended. now i'll be able to rinse using the black water line at the dump stations quickly and not bring home that "bottom of the tank" residue that never just dumps clean. my only issue is now that i've tested it, a little water stays in the line and now that it's freezing, i don't know how to get it out of the hosing. air pressure didn't work, nor did suction since the water is trapped in the hosing between the connecter on the trailer and the connection to the tank. i left the cap off in case that little bit of water freezes. otherwise a clean, fast convenient solution for really getting the black water tank cleaned out. no more false sensors.