Much like how you used to be able to move the window to do the "fake blink" or "lag teleport".
Simple. Click the window. Click it over and over and over.
Put your WoW into windowed mode (Main Menu>Video Options>[ ]Windowed Mode)
While moveing forward click the window (On the part it says "World of Warcraft" .. at the top) over and over fast for how everl ong you want to lag for. Once you stop you seem to stay in the exact place, but your character's "ghost" image appears to have been running the whole time, then suddenly shoot back to the spot you started in.
Works pretty much the same as the sit-stand macro but not as laggy, no D/C chance, (Unless you have a terrible connection maybe) and simpler for some to use.