I use my black tank flusher when using the sanicon when getting close to empty. The sanicon cannot do its job if "stuff" stays in the tank. I know it is against the manuals but after finishing dumping, I leave the flusher on for a few moments to add back liquid to the back tank to reduce the possibility of TP or solids making pyramids or blocking the sensors. We have two baths. The half bath is right over the black tank and is a foot flusher (little water use) so we try to use that one for #1 business. The rear bath is a macerating electric throne which uses more water so we try to leave that one for #2 business. We can go longer before having to dump with this plan and have not had odor or other issues so far.