Completely cover ears of corn with cold water in a large pot. Soak for 15 minutes.
Meanwhile, preheat grill to medium.
Remove ears from pot and shake off excess water. Pull husks back, being careful not to completely remove the husks. Remove and discard long strands of silk.
Brush exposed kernels with oil. Rewrap each ear of corn in its husk.
Grill for 15 to 20 minutes, or until corn is tender. Be sure to turn ears frequently. Remove husks and if cobs are not charred to your liking, return cobs to grill for a few minutes.
Notes
For extra flavor, top grilled corn cobs with squeezes of fresh lime, crumbled feta cheese, shaved Parmesan, or smoked paprika.