Summarize this article in one sentence.
Place the sand dollars in a container filled with fresh water. As the sand dollar sits, the water should start to get brown. When the water gets to be a murky brown, replace it with fresh water and submerge the sand dollars again. Keep swapping out the water and submerging the dollars in fresh water until it stops turning brown.  Fully cleaning the sand dollars could take anywhere from 1-3 hours. Sand dollars can be found in shallow water, in the sand on a beach, or under seaweed. Pour 1 part bleach and 3 parts cold water into a bucket or container to create your solution. This process will whiten off-white or brownish sand dollars. Wear a pair of rubber gloves and carefully place the sand dollars into the solution to bleach them. Do not soak the sand dollars in the bleach solution for too long or they can crumble. Run the sand dollars under cold water from your faucet to remove the bleach and water solution. Leave the sand dollars in a sunny place for 1-2 hours to dry them. Let the sand dollars completely dry before moving onto the next step. Pour the PVA, or white glue, into a container and add an equal amount of water. Mix the solution together with a wooden stick or a brush until the glue and water are mixed thoroughly. Applying this solution will harden the sand dollar and make it easier to paint on. Elmer’s Glue-All is a popular type of PVA glue. Dip a paintbrush into the glue and water solution. Apply the solution liberally over the top surface and underside of the sand dollars with large, broad strokes. Lay 2 chopsticks or toothpicks on a table so that they are parallel to each other. Then, lay the sand dollar over the sticks so that the chopsticks or toothpicks prop the sand dollar off the surface of the table. This will serve as a makeshift stand and will prevent the solution from coming off the bottom of the sand dollar.
Submerge the sand dollars in fresh water to clean them. Soak the sand dollars in a bleach and water solution for 5-10 minutes. Rinse off the sand dollars and let them dry. Create a 1:1 mixture of water and PVA glue. Coat the sand dollars with the glue and water solution. Lay the sand dollars on 2 chopsticks and let them dry.