It's all been said. Bottom line is you need to flush with a full tank and then refill and flush until it runs clear after each camp outing. A clear plastic flush extension helps with monitoring the fluid to make sure all is running clear. I continue to refill the tank and empty until I reach that state. It's easy if you have a black water tank flush accessory, otherwise my routine was to use a hose and fill the tank from the top of the toilet. Usually only one extra top off.
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