After three odd years of use, we noticed that the inside wicking bed connected to the kitchen sink was not distributing the water properly. We dug up the two ends of the 4" drainage hose and discovered it was largely filled with greasy, gunky, nasty stuff.
We pushed a pipe through, with a cup on the end that filled the 4" pipe. It pushed all the gunk through and we then scooped it out. We then stuck a hose in and washed it all clean.
The system now works great again, but we figured it was a job we would rather avoid having to do again in a couple of years.
We disconnected the kitchen sink from the drain pipe. We then put an old kitchen sink under the sink, in the cabinet. It's plug is connected to the drain pipe and the real sink's water drops into it. Inside the filter sink we placed two rectangles of 1/2" PVC on top of each other. A shade cloth is attached to one, nylon to the other.
It all works great. There's no splashing and it all drains through quickly. The shade cloth, which catches the larger chunks doesn't actually catch that much, as most of the large stuff is caught by the sink's screen. However, the nylon does catch a lot and I'll probably need to clean it every 4 or 5 days, which is no big deal as it is easy to clean and the bacteria that cause grey water to stink haven't had time to get established.
A quick, cheap and easy solution to a nasty problem.