Nothing requires the black tank be flushed every time you use the trailer. The flushing is more of a ...makes the owner feel good thing. If there is no line, I take my time and don't rush. If there is a line, I get things as ready to go as possible before I pull up, then dump as quietly as possible....NO FLUSH Out, sore the stinky slinky and pull out so the next person can take care of business.
Too many campers have no concern or consideration for their fellow campers.
At a roadside rest area with a dump, I pulled in right behind a motor home to dump. He gets out, gets the hose out and pulls the black valve and goes inside and does not come back out. Several minutes go by and he is not to be seen, has not dumped the gray tank yet. I finally got out, walked up by the door and hubby and wife are sitting at the table, having lunch, TV antenna up and watching TV. I told him I had been waiting XX minutes to use the dump station. He informed me that he would finish up after lunch. I told him this was not a parking spot and get it finished or I would see about moving the motorhome.
By this time we had another RV in line to dump. He walked up to see what the hold up was. He was not as polite as I was and told him to move the ^&)%&_( junk and eat else where. At this point he came out with his sandwich in hand and finished dumping....YUCK. I know the clown was there for over 20 minutes. He finally pulled up and I had to honk at him to get him to move up enough that I could get to the dump. I was out of there in less than 5 minutes. As we maneuvered to get the truck and trailer around him, his lovely bride flipped me off. Just goes to prove that there are lots of A-H's out there. I hope she did not flip -off the guy behind me,me would have come unglued.
Ken