I've tried many things on Coticules and also find my best edges come from dry honing. Controversial to many, but I've found the edges to be excellent for my personal taste. I prefer them over oil or water. I find them very keen, but really smooth.
So I figured why not try honing on the 20K dry? I can already hear people cringe, but it worked very well for me.
I did enough laps on the 20K dry followed by a superb linen and horsehide strop by Scrupleworks with great results. The edge felt smoother than ever coming off of the 20K.
Outstanding edge and shaves. Will undoubtedly finish more razors on my 20K dry.