Depending on how close together your pedals are and how big your feet are, you can accomplish a hell-toe without actually using your heel and your toe, but rather with each side of your foot.

For example the pedals in my car are really close together and I wear a size 12 shoe, so I just put the ball of my foot on the right edge of the brake pedal and tap the left edge of the gas pedal with the outside edge of my shoe.