How to cook corn kernels on BBQ

The best way I have found is to soak the ears in husk for several hours before grilling. This lets the husk soak lots of water. Then place the corn, still in husk, on a hot grill for about 10 minutes, ~1/4 turn, 10 minutes, turn... until the husk gets brown, even burnt.

You should be able to tell when the corn is cooked by the smell. The sugars in the corn will start to caramelize and brown in the husk and it will give off a delicious caramel smell. You can check them by peeling down the husk to make sure that they are cooking well.

Times will depend on your grill and how much patience you have. In general, it is difficult to overcook. You want to watch out for drying, but that usually takes a while if you soak the ears beforehand.

Foil is a poor substitute for the natural wrapper. The husk both protects the cob from too much direct heat as well as holding water close to the cob to gently steam the kernels. And its just prettier with the browned and burnt husk, au natural.

Lately, I've been direct grilling them fully stripped of the husk, with a brush of olive oil first. Its relatively quick, but requires a bit of attention as you'll need to turn the ears. You don't want the heat too high and it can be difficult not to dry the corn out.

It produces a distinct favor but its absolutely wonderful, everybody raves. The slight smokiness and carmelization of the sugar in the corn heightens its favor considerably. It produces a much different result than grilled corn wrapped in foil (which is essentially steaming the corn) or boiled corn. Grilling in the husk is another common way, but its a much different result and not too different from grilling it with foil.

It was brought up in the comments, but the most 'modern' correlation to boiling the corn like you said, would be to sous vide it. It's definitely 'modern', but sous vide is not quick. It does preserve and intensify flavour well though.