Last year was the first year I did it. I made sure to add water do the level was above the boil line and left it a month. I then drained it and flushed with water. Then turned it over and cleaned the bottom with oven cleaner. Last thing I did was power wash inside and out. I have a 2 by 6 so it was easy moving things with 2 people. Have no idea how the big guys clean the flues. My pans looked like new. I'll never clean another way unless someone comes up with an easy way to clean the bottom
20 plus years of 2 by 2 flat pan
2014 new Phaneuf 2 by 6 drop flue
350 taps on gravity 20 on bucket