K.M.
Ok, so I like to dip Ruffles and Pretzels in Chocolate and I find that using butter with Nestle choc chips is the best method.
I suggest you use the double stuff oreos and instead of taking them apart you should be able to stick the stick in the frosting easier that way. Freeze the oreo cookies BEFORE you dip them, dip them once ... freeze dip again, Freeze and Dip once more if you like for good measure. I like to do Dark choc, White choc, Milk choc, where you can see the gradiation of chocolate but since it is an oreo it could be fun to do dark/milk then white then dark/milk again ALL over it could create a GREAT look after you take a bite! Freezing is going to be a HUGE tool and time consuming I know but WORTH IT!!!