Like others I usually like to clean my tank however I don't do it while at a dump station. Even though I can dump at home I usually prefer to dump before heading home. Once at home if I think I need to I can clean my tanks to my hearts content.
I have posted this here before but I did have one incident at the dump station that tried my patience. A guy with a brand new 45' class A was dumping. He then decided to pull up just enough to reach the fresh water fill and block everyone in. He proceeded to use a very small hose to fill his completely empty fresh water tank while we all got to sit there and wait on him. What made it even worse is that he had just left a camp site that had a water hook up. While waiting we also found out that along with his new motorhome came with a new blonde wife who was at least half his age. He was very proud of both of them. Can't say that he made much of an impression on those of us waiting.