I have 2012 cruiser and have washer. Wife was washing load and yelled at me that the toilet was filling up. I had just drained the gray tanks but was in state park with no black tank dump. I drained some out of the black tank but will not tell where, I was also surprised that crossroads had plumbed washer into black tank, guessed it was easier than doing it right as was most of the light switch placements. we have learned to just wash when have sewer connection but would like to connect it to gray tanks. Water for washer would not have any odor to drain on grass or trees but most parks do not allow.
I will be interested how you re plumb it if you do.
Sonny and Peggie Crist
Broken Arrow, Ok