Wayne & Rebecca, Thank you! Seems certainly more difficult to accomplish than I thought it might be.
How about this... I am building 1-2 degree off contour swales on a big section of the property with tiny ponds at ends. What if I were to take the grey water to the “top” of the swale system and let it gradually filter threw the swales. That seems like that work work, right? Worst case I would need a heavy mulch basin at the first collection “pond” to filter the water quickly to remove odors.
Save the rain water for the animals and send the grey water to the plants.