Begin by crushing the 8 oreos in a food processor (you can do by hand, but it takes longer). Add half the mixture to one large zippered baggie, and the other half to a second zippered baggie. Set aside.
Set out two large bowls. Place 4 c of cereal into one, and 2 c into the other. Set aside.
Take two small bowls and place the milk and semi-sweet chocolate in one and the white in the other. Pour 1 tsp of oil in with the milk and semi-sweet chocolate. Pour the other 1/2 tsp of oil in with the white chocolate. Melt the bowls separately.
Once the chocolate is melted, pour both bowls into the bowl with 4 c Rice cereal. Stir gently. You want all pieces to be mostly covered by the chocolate, but you don't want to crush the fragile cereal.
In the other bowl of cereal, pour the 1/2 c of caramel and salt over the cereal. Stir gently.
Once both cereals are mixed and coated, pour each bowl into the zippered baggies. Zip them up, and shake until the oreo crumbs have stuck.
Open the baggies up, and in the bag with the chocolate, pour 1 c of powdered sugar into the bag, and shake until completely coated. In the caramel bag, pour 1/2 c powdered sugar into the bag and shake until completely coated.
Enjoy!