Flush with cool water, then apply a detergent or an all-purpose stain remover with enzymes directly to the stain (look for proteases, amylases, lipases, or cellulases in the ingredient list). Wash the garment in warm water with an enzyme detergent and an oxygen bleach (such as Biokleen Oxygen Bleach Plus). It breaks down the chemical bonds in the stain, making it vanish.
Dunk the clothing in cold water, then soak the stain for at least 15 minutes in equal parts water and rubbing alcohol (it's safe for most fabrics when diluted). If that lifts the stain, toss the item in the washer. If it doesn't, soak the spot again in equal parts water and white vinegar before you wash it.
Baby Oil, Cream, and Petroleum Jelly
Remove any excess glop, then sprinkle the spot with talcum powder to absorb the oil. Wait ten minutes, scrape the area with a spoon, then treat it with a stain remover (such as Caldrea Stain Remover); launder the garment.
Formula or Breast Milk
Soak for a few minutes in warm water before adding an enzyme presoak (such as Biz) to the water. If the spot lingers, treat with a stain remover and wash the item.
Shake any, er, solids into the toilet, and soak garment for at least 15 minutes in cold water with an enzyme detergent. Apply more enzyme detergent to the stain and launder in cool water. If the stain remains, soak in oxygen bleach. When stain is gone, wash garment in very hot water to sanitize. Dry in the sun to bleach further.