After I am done I just hook up my compressor and blow air through, takes about 10 minutes. The method I have had the best success with is a real fine silica sand used for sandblasting. Salt works great but is a PITA to clean out. Filling it with water is the easiest to clean but if you get the slightest air pocket then your going to have trouble. When I use this method I have done it without kinks but have a slight flattening this still works great but I think the water flow is slightly restricted from what I've tested. Doing it using Hooklines method without salt works but takes a lot of patients and you have to turn it slowly. I've made a lot of coils, with just about every technique that has been mentioned on the site.
