Its an oldschool thing. You can make some great ammo using a dipper. You will find some guys on here who swear by them (Lost Sheep stills dips I believe, at least for some calibers). Most of that crowd will fashion their own dippers from an empty case trimmed to the correct length, affixed to a length of stiff wire as a handle.
I have great respect for reloaders who make quality ammo with simple tools. I am all for those who use a chargemaster to throw the perfect charge too, but there is something to be said for simple techniques. If the S ever HTF, simple is better