Rid-X

Been a topic of conversation since the beginning of self-contained RVs. It is not a good idea, but a harmless waste of money. The fact is that you have a HOLDING tank under the RV toilet, not a septic system. The goal is to keep the contents of the tank well liquefied to allow for easy and complete discharge, and to control the odors, that's it. If you allow the contents of the tank to remain long enough, they will begin the process of anaerobic decomposition, just as they would in a simple septic system. That said, this process is not necessary, or intended when using the holding tank.
Remember, these type of products are marketed by companies that need you to believe that they are necessary. They are not necessary in a properly functioning residential septic system, and they are just a waste of money in a camper.