Periodically clean plastic bath toys to protect against mildew growth. To clean toys, soak pre-washed toys in a solution of 3/4 cup bleach (or 1 cup vinegar) and 1 gallon of water for five minutes. Make sure to suck the cleaning solution into squeezable toys (such as ducks and squirters) and shake it around to clean the toy inside and out. After five minutes, squeeze excess cleaning solution from the toy and rinse thoroughly with hot water.