Hasta La Motion!

Hi,
Ok, I have a question that has been driving me nuts for weeks.
Its the old….stabilize,paint unstablize trick.

From what I understand, one technique would be:
Stablize a moving shot, do your wire removal or paint, and then put back the motion.
Ok, So you would…track the shot, (now you have "tracking data")
then use the "tracking data" and reverse or stabilize the shot.
Now the shot is "stable" and now you (for example) paint a patch of grass to cover up the wire .
Then you unstablize and well-la…a perfect wire removal.

So here is my question:
What’s the difference between doing it that way .OR…applying the "tracking data" you got when tracking, and apply it to the grass patch?

I don’t understand the difference?
Thank you,
Lou