No doubt , it would only be benificial to stop the purge around the outside diameter of the Ball joint .
I'd say there's no seal , most likely just a thermal pressed install , which creates small scores on the I.D. of the Bore that the Ball joint is thermally pressed into , therefore creating a path of least resistance for the grease .... unless more comes out than you put in I just wouldn't worry about it , because the Balljoint assy does not require much grease at all Sir .
Most ball joints do not even have a grease fitting .
HOPE THIS HELPS !
This is just my opinion friend , so make your own analysis .
Know this : I'm from Arkansas, so obviously I'm of a higher intelligence than anyone else Ever !
GO HOGS !