I lurked on this thread to learn how to do this in my own game. All's well for me - let me see if I can clarify how it works a bit for you:
When you, in a Move Route event, run the " @original_pattern = n " script, what it does is change the event's default, resting, idle animation frame to the given number. By default, a sprite has 3 animation frames, 0/1/2, and when it's standing still it rests at 1. If you ran @original_pattern = 0, then they'd still do their walking animation when moving, but would stop at the leftmost frame instead of the middle. This behavior persists until you change use the script to set them back to frame 1. If they're already standing still, the change should be instantly visible once you run the script (though I've seen it bug out once or twice).
As far as I can tell, this script does nothing (it is probably the wrong syntax) if you put it in an actual script event, or one of the game's overall scripts. It HAS TO be in the Move Route, nothing else will do.
The screenshot you posted should be working, except that most sprites don't have any frames besides 0, 1, and 2. Also, as Shaz pointed out, "Turn Down" and such won't do anything if the sprite is already facing that direction.