I don't have a ball valve in mine, so I don't worry about that. Since it's just a basic brew kettle, I really don't worry about the "Cleaning" aspect of it all that much. Basically, when I'm done brewing, I immediately hit it with some hot water and scrub it to make sure I get all the crud off, to me that's all I really think I need to do. Every once in a while I'll notice a little build up on the bottom, if that doesn't come off with hot water and my scrubbing pad, then I go ahead and soak it in PBW make sure it's nice and shiny again.
Usually, after the hot water and scrub though, it looks pretty shiny, so I just don't see a need to attack it and clean it like crazy.