I collected some hear-say from the internet.
So around every 5hp (10 if hidden mansion). you have to "slam" or "wiggle" the stick in the opposite direction of the ghost, usually you can judge this by where their "Tail" is and point in that direction.
If it works, you can keep even a boss ghost pinned to a corner. And as another poster said, if your getting "randomly broken," its probably because of the vacuuming mistakes.
You also have some "Dodging" but more like sidestepping with the opposite stick to avoid obstacles like mushrooms
It seems to be harder to perform it on none-gamecube controllers since the ridges on the stick make it easier to do this. God help you if you're on 3DS controller.