Always use an RV holding tank treatment at least once a month, to prevent blockages and keep your system smelling fresh (well as fresh as it can do). You can also use RV toilet paper that will break up easier than normal paper, thus preventing clogs. Always empty the black tank first, then the grey to flush down the debris. Close the black and grey tank valves when camping, you want the tanks to be close to full when you dump them, so gravity can do it’s magic. Only put toilet paper down the toilet, other trash and femminie products will block up the system in no time and you’ll have to get your hands dirty.