How do you efficiently clean a leek? I've often found dirt deep within a leek, under several layers. Going through it all can be a very tiresome process. Is there any trick  you can use to clean a leek, without cutting it up and ruining it's natural shape?
Trim the tops and discard the out leaves. Then cut from 2 or 3 inches above the root to the top, turn 180 degrees and cut again (they should look like the picture).

You can then get the water down inside and get all the dirt out.