Preheat grill with lid closed to 350° Fahrenheit. While grill preheats, place one russet potato in medium bowl. Prick potato with fork then coat with neutral oil. Set potato aside and repeat with remaining potatoes.
Pour salt into second medium bowl, using enough salt to fully cover bottom of bowl. Place one oiled potato in bowl and flip until potato is coated with thin layer of salt. Transfer to microwave-safe plate or bowl and repeat process with remaining potatoes.
When all potatoes have been oiled and salted, place in microwave. Microwave all potatoes together on high for 4 minutes. Remove potatoes from microwave and wrap each potato securely in 2 sheets of aluminum foil.
Place foil-wrapped potatoes directly on grill grate. Shut grill lid and grill potatoes 30 to 40 minutes, with lid closed entire time. Note: grill time will increase every time lid is opened.
Begin checking doneness of potatoes after 30 minutes by slightly unwrapping one potato and piercing skin with fork or skewer. When fork or skewer pierces completely through potato easily with no resistance, remove potatoes from grill.
Unwrap grilled potatoes and discard foil. Cut potato open by slicing lengthwise down center of potato, then gently press ends of potato to open wide. Fluff potato flesh with fork and serve immediately with desired toppings.
Important: Make sure that your grill is fully preheated before you add the potatoes.
Refrigerate leftover potatoes in an airtight container up to 5 days.