You can put all the oil, salt and pepper on the outside of a sweet tater you want. It will not penetrate the skin. People will tell you that the smoke will penetrate the skin, but it won't. The flavor of the sweet tater comes from the carmelization of the sugar with-in.

We here in the real south brush them lightly with oil to keep the skins soft while cooking. I usually wash mine off and wrap them in foil while still wet. Has the same effect.

They get baked at 350 (indirect) till the are easy to squeeze. Let them sit for a short while. The skin should peel right off with your fingers. Mash them. Add some butter, sugar and cinnamon.

YUMMM!!! Best part is even with the butter and sugar they are better for you then white taters.