Preheat oven to 400 degrees Fahrenheit (200 degrees Celsius).
Scrub potatoes clean and pat dry. Pierce each potato multiple times with a fork.
Rub potato skins with vegetable oil and salt, then place directly on oven rack or a baking sheet.
Bake for 45 to 60 minutes, or until skins are crisp and the centers are tender when pierced with a fork.
While potatoes bake, brown the ground beef in a large skillet over medium-high heat until fully cooked. Drain excess fat.
Stir in taco seasoning and water. Bring to a simmer and cook for 5 minutes until the sauce thickens.
Remove potatoes from oven. Slice each potato lengthwise and fluff the interior with a fork.
Top each potato with equal portions of seasoned ground beef and shredded cheddar cheese.
Finish with sour cream, salsa, green onions, and jalapeƱos before serving.