We made dipped Oreos to give to our neighbors as gifts this year. I just melted candy chips in the double boiler and dipped the Oreos in. I used a bamboo skewer to hold the Oreos and a spatula to cover them with the melted candy. This worked well for the mint chips I used, but the white chocolate was very thick and much more difficult to work with. As a result, they aren't as pretty.
I figured the cost of this project out to be 16.66 cents per Oreo. 2 12 ounce bags of chips covered 1 package of (45) Oreos. John and Maggie decorated the bags, which we already had.