A camper septic system works by simply acting as a holding tank for your sewage. Water you use in the shower or sinks goes into a separate holding tank for RV use. All the waste water stays in the trailer holding tank until you open the corresponding valve to dump it. This is what RV septic systems do.

Is it OK to use bleach in RV toilet?

Cleaning your black water holding tank is best done when youre fully hooked up and have both a water and sewer connection. Avoid using bleach or antifreeze for your deep clean, as both of these can dry out rubber seals and ultimately ruin your sewage system.