Been cooking corn that way for years, and by trial and error came to the same four minute microwave time the video mentions for average sized ears. For even cooking I turn the ear over at the two minute mark. Rarely do we have worms in our corn anymore, but if so, they cook and are cleaned off afterward.
Microwaving whole unshucked corn releases a lot of steam into the microwave so I added one step last summer. I wrap a small rubber band tightly around the silk end of the ear, to seal off the "open" end of the shucks. That reduces moisture released inside the microwave by half or more, a factor if you cook several ears in succession. I destroyed one microwave several years ago by cooking several ears one after another and the moisture built up into the electronics and fried the unit with a small fire.
For freezing, I let the ear cool as it is, unshucked, and then seal wrap the unshucked ear in Saran wrap. Microwave the frozen ear for four minutes.
We cook ears of corn in a campfire the same way: wrap whole unshucked ear in aluminum foil and bury in the coals for a few minutes. A shovel helps. Bury the foil wrapped ear completely, because if part of it is uncovered and exposed to the air, it will scorch and burn the corn at that point.
Love corn cooked that way!