Chop off fuzzy tip from ears of corn. Soak ears of corn in a pot with salt water for about 30 min. On a BBQ grill, place ears of corn over fire. Turn frequently until husks become charred. Take each ear and pull back the husk, exposing the corn on the cob. Leave husk for presentation or just pull off completely. Place corn back on grill. Turn frequently until corn kernels become charred (brownish). Once your corn is ready, take each corn, slather with butter, slather with mayonnaise, sprinkle Parmesan Cheese, and finally sprinkle Tajin seasoning to taste.