A finished wash is not proof that a mark is gone. The American Cleaning Institute recommends checking before drying or ironing: this helps keep a remaining stain from becoming permanent.
Look at the actual item after washing. If a mark remains, use only the next step allowed by its matched guide, care tag and product label. Do not invent a stronger mixture.
For someone learning laundry, this is a useful pause to practice together. Checking is a separate job from pressing Start.