Create a paste of one-half cup baking soda, one-quarter cup white vinegar and 1 tablespoon liquid dish soap. Stir the ingredients, and add more baking soda if the paste is too runny.
Dampen a kitchen sponge with the baking soda paste, and work it vigorously into the stain. Continue to work the paste into the stain until it is eliminated.
Wet a rag with plain water, and wipe away the baking soda paste. Dry the padded toilet seat with a separate rag.
Slip on a pair of rubber gloves before creating a mixture of one-quarter cup chlorine bleach and three-fourths gallon plain water. Stir the water until the bleach is well-incorporated.
Wet a clean cloth with the chlorine bleach, and work it into the toilet seat stain. Allow the bleach to remain on the seat for at least 30 minutes before continuing.
Wipe down the toilet seat with a damp rag to remove the chlorine mixture. Dry with a separate rag.