ScottG's device is probably one of the best to use. I have the store bought version and it shoots water 30 feet from the wand, very powerful. If the camper sits stationary, this is the item to use. If you travel, the sloshing of the tank with laundry soap, or almost anything used in the laundry or washing dishes will clean the tank and sensors. It's the vigorous sloshing against the sensors that cleans them.