One popular option many RVs have is a fresh water rinse system for their holding tanks. Some rigs have one for only their black water tank, but others may have such systems for all of their black and grey holding tanks.
Sometimes these systems are OEM from the manufacturer; others are installed by the dealer as part of the sale, and RV owners sometimes install them themselves.
A tank rinse system is basically a nozzle built into the side of the holding tank that allows clean water to be sprayed into the tank inside. Typically this is done during the dump process so that the tank is empty, and can be flushed when rinsed.
There are predominantly three popular rinse systems available on the aftermarket. They are:
Both Camco systems are reasonably priced at $20~30, while the Valtera system can cost as much as $60, which I view as over-priced.
Regardless of which system you chose, installation consists of drilling a hole in the side of the holding tank and screwing the nozzle into the hole. Silicone is typically used to seal the hole. There is some chance of leakage, however minimal, and depends on your skill at installing the nozzle.
The Camco Quickie Flush seems to favor a heavier spray closer to the nozzle; the Valterra No-Fush Flush seems to spread the spray out more evenly, and I could not get the Camco Tornado to work properly.
Note that the Tornado requires 40~60PSI to work properly, and my water pressure was about 38PSI, so the Tornado would not spin. Had it worked, it potentially offers a good spray pattern.
Since these nozzles have to perform in a variety of locations, adequate pressure cannot be guaranteed, and in fact it is more likely that pressure under 40PSI will be a common occurance, especially at a dump station. For this reason, we did not like the Tornado and cannot recommend it.
Of the two non-spinning units, we liked the spray pattern of the Valtera No-Fuss Flush the best, but not at a $60 price tag. Seems to us the Camco Quickie Flush is the best option of low price and good performance, providing you can install the nozzle close enough to the tank sensor probes for them to be cleaned.
"Tank Rinse System Shootout Video"
"Installing the No-Fuss Flush tank rinse system."