You don't do it unless it's appropriate. It would obviously only be appropriate against another staff or other long pole weapon, like a spear. That's what most staff techniques were designed to deal with, I believe.
You deflect their weapon down when it is thrust at you. If they use that motion to continue their attack by circling up to strike you, you maintain contact with the weapon to control and circle it down again. If you manage to trap their weapon down at some point, or otherwise make them lose control or pause, then you strike. If they do something else to attack you, like bring around the other end, then you react acordingly.
Alternatively, you may just be reacting to repeated thrust attacks (which are easy to deliver in rapid succession).

I see the forms as a representation of a strategy, not a technique to be repeated verbatim. In other words, the form may have you performing five circles in a row, this does not mean you must always do five circles in a row. You do as many as you need to...maybe one, maybe ten. The form simply addresses the possibility that you might have to do more than one circle before countering.