You need to be level 89+ and first you need to complete enough Dread Wastes quests to get dailys at klaxxi.
The quest we need is not up every day but once you have it you can use it any day no matter what dailys your realm has.
You need daily Rampage Against the Machine - Quest - World of Warcraft ->
Accept quest, go south around 50 / 40 where you can see Kovok.
Go near Kovok and spam right click while moving and jumping.
It is not gonna usually happen in first try so you need to do it again around 10 times... you know you are in right phase when you see a lot of mobs front of you.
In the right phase a whole pandaria is empty except these "Rampage against the machine" daily quest object mobs. You might also find few mobs from selected areas because they have own phase there... like Krasang wilds PvP area.
Now you can freely gather materials and do archaeology without getting interrupted by monsters.
Enjoy!
