Dunking is somewhat of an art. You can get step-by-step directions with pictures here.
There's even a gadget for dipping called the Dipr.
The Oreo name has changed several times over the years. When it was introduced in 1912 it was called Oreo Biscuit .... then Oreo Sandwich (1921), Oreo Creme Sandwich (1948) and Oreo Chocolate Sandwich Cookie in 1974.
The formula has changed, too. In the mid 90's the lard was replaced with trans fat which in turn was replaced with non-hydrogenated vegetable oil in 2006. Apparently in Canada, coconut oil is used. I can't verify this 'cause I don't have any Oreos in the house right now. (for shame!)