In order to wash your American Girl Doll's hair, if she has short hair, you will need the following: Scotch tape, cotton balls, a towel, and Johnson and Johnson baby shampoo or wig shampoo. Usually, you will need to avoid getting the dolls wig cap wet. First, tape your dolls eyes shut. Place a cotton ball over her eyes first. Use a nozzle sprayer to wet her hair. Gently shampoo her hair. Try not to scrub it. Let it sit with shampoo in it for about 3 minutes. Rinse gently. Place the doll on a flat surface, with her hang over the edge. Place a towel on the floor to protect it, as the hair drip dries.