If you have the time, I've found the best way is to rub with a little olive oil or butter, sprinkle with sea salt, wrap in foil and cook right on coals. But, the microwave works just fine if you wrap them in a paper towel and wet the towel well.
Man that picture takes me back.
When I was in college at Bemidji State College, our dorm had a built in, INDOOR charcoal grill. (You don't see those any more.)
We baked potatoes just as that photo shows and a wave of nostalgia hit me big time when I saw it.
There is no potato better than one cooked over direct heat, i.e. flame or red- hot coals.
There is a difference between a flame and a electric oven.
I don't mind nuking them a bit then foil wrapped and in the coals or on the grill in indirect heat for the smoky flavor, think I will fire up the Weber for the first time this season and get a burnt offering going for this Sunday.