Are you talking about a bleeder ball, that you attach to the master cylinder lid and pump on? If so they work great if you have the right fitting for your vehicle. But honestly they arent neccesary. Also why are you flushing your lines did you get water in them? If not your talking about bleeding them. Which if you install speed bleeder valves is incredibly easy. If your putting on a new master cylinder there is another method for that which uses a kit that usually comes with it in the box.
The Last Great American Hero... the demi-god... to which speed means freedom of the soul.