That's the same as we do other than the Chlorine. The way I read your post I thought you weren't using antifreeze, that peaked my interest. Perhaps we will try the chlorine this spring.
Curious how are you doing it now? I have always drained the tanks and then run antifreeze through the system till it is drained. In the spring I flush a few times, the first time using a cup of bleach. I have always only used the water in the tanks for washing, not for drinking.