Scrape the toothpaste off the clothing with a dull butter knife before you treat the stain. Remove as much of the excess toothpaste as possible without spreading it across the surface of the fabric so that you can treat the stain directly.
Pour rubbing alcohol onto a sponge to dampen it. Blot the toothpaste stain from the center out to the edge. Avoid rubbing or pressing down too hard because you can cause the stain to become worse.
Combine 1/2 tsp. mild liquid dishwashing soap with 1 tbsp. white vinegar. Add the solution to 1 qt. warm water and soak the clothing in the solution for 15 to 20 minutes.
Remove the clothing from the warm water solution. If the toothpaste stain remains, soak it in a solution that consists of 1 tbsp.of a commercial presoak product and 1 quart warm water. Leave the clothing in the solution for 30 minutes.
Apply a prewash stain remover directly to the toothpaste stain if you have difficulty removing it. Follow the directions on the prewash before you apply it to the stain.