Sewage smell, also how do you clean your tanks?

Rinsing the tanks and adding chemicals isn't going to solve the problem. If you have an odor inside it because something in the system isn't working properly. Because you are using the rig I think we can rule out a dry P trap. So the next place to look is under the sink or counter for a vaccumm breaker that is malfunctioning. Just follow your nose and you should be able to find the source of your problem.