I recently found a spare ball valve at SB headquarters that hadn't been cleaned down properly post brew, so thought this was a good opportunity to demonstrate the right way to do it.
First remove all the seals. The amount of moisture left on the seals (and even some mold it looks like) indicates that at best this ball valve was only rinsed off post brew. This is less than ideal, and can risk the longevity of your ball valve.
Once the seals are off, remove the hose barb, unscrew the bolts (being careful not to lose any nuts or washers), and remove the outer housing.
On this ball valve, you can see the white plastic seals that hold the ball in place. These can be popped out, and the ball itself removed (To remove the ball, turn the handle to the closed position, the ball can then slide out). Notice after I removed the ball, there was some liquid left in this cavity. If this isn't cleaned out, it can infect future brews, as it will be released during transfer when the valve is opened.
I then made up a mixture of PBW in hot water as per instructions on the label, and soaked all of the parts for an hour or so. I also wanted to clean the racking arm and trub damn. This appeared to have been cleaned post brew, but to be safe, I threw them in anyway.
After all of this, I cleaned all of the parts down with a soft cloth in the PBW and rinsed off. Finally, I air dried all parts in a sunny spot in my kitchen.
Once dry, I reassembled the ball valve in the reverse order that I broke it down.
Finally, before I use this part again, I'll sterilise by running a Star San solution through it to make sure everything is good to go on my next brew day.