I've heard about using the blue tote for dumping so you don't have to move the rig. When the tote is not as large as the tanks you are dumping from do you just have to wing it and hope you shut it do...
I've used my tote many times when camping at a state park. It saves me from having to drag the TT to the dump station. Once I dump the tote, I clean it out real good with bleach and water, and haul potable water back to the TT. It kills two birds with one stone. Trick is to make sure the tote is very clean inside.