In Strand of the Ancients, its REALLY easy to afk without people being able to report you at all.
First off, it would be helpful if you had some form of water walking. This can be done through Water Walking (Shaman), Path of Frost (Death Knight), Or Elixir of Water Walking (Crafted, or Fishing drop)
Now take a look at the map. When the game starts, two boats come from the top of the map. The trick to being able to afk in this battleground is to run up to where to boats spawn (outside of the map range) and simply wait there till your group wins or loses.
When you sit at this spot, people cant see you on the map and cant report you afk. Although they can still report you through your character portrait, if they don't know you're doing it, you cant be caught.
Keep in mind however, when the 3.3.3 bg changes roll out, you'll get even less honor from winning and more from HKs, and there wont be any afk marks to farm.
I searched and didn't find anything like this, so if its a repost, I'm sorry