Quote Originally Posted by Sepho
The slots don't actually slow down. The repeated interrupting of the rhythm caused by mashing the square button gives the illusion of the slots slowing down. Either way, it's still an effective method, and with a little practice you should be able to pick whatever handicap you want with a decent level of consistency.

It's a good way to break all your materia and maximize the BP you get from fighting in the Battle Square.
There it is.

Yes, It's certainly a good method, and one that's served me brilliantly.