Gray tank cleaner

I put in about 2 cups of liquid laundry detergent in each of the gray & black water tanks & fill them about 1/2 - 1/3 full for the final drive home at the end of camping season. For the galley tank, I empty the hot water tank into it to help break up the nasty kitchen grease.

I prefer the HE laundry detergent because it is very low sudsing and so drains more completely.