Lay out a clean, absorbent cloth and place the stained item onto the cloth with the stain facing down.
Moisten another cloth with water and add a small amount of laundry detergent to that piece of cloth.
Dab at the foundation stain with the cloth to begin removing it. Work from the outside edges in, toward the center of the stain. This will help keep the stain from growing.
As the stain begins to transfer from the clothing to the absorbent cloth placed underneath it, pick up the clothing and move it to a clean area of the absorbent cloth.
Keep working at the stain until you remove as much as possible.
Wash the clothing in the washing machine, using the warmest water that is safe for the fabric. Check the item after the wash cycle finishes. Do not dry the clothing in the dryer unless the stain has disappeared. If you place the item in the dryer with some of the stain still noticeable, the heat from the dryer will set the stain, making it very difficult to remove.