Dish soap provides sensory input by itself because it is already slimy before it is added to water. By putting dish soap in sponges and working it into lather, the two will work together to create a new sensory experience. The texture of the sponge is drastically different from the smooth soap. The kids can squeeze the soap lather out of the sponge and make bubbles in the water while allowing the lather to run over their skin. Challenge the children to see who can make the biggest suds tower before it tips over to keep kids engaged.
Marbles can provide input to several senses as at once. They are smooth and round, which provides texture input. They are also colorful and come in various sizes, which can simulate the visual senses. By placing several marbles in the bottom of a water table and covering them with water, children can experience the optical illusion of water along with the challenges of grabbing smooth, slippery marbles. Use magnetic marbles and magnetic fishing poles to allow the children to go on a treasure hunt for precious gems.
Small styrofoam balls that are used to fill bean bags are great in a drained sensory water table. Fill the bottom of the water table with the styrofoam balls and bury small objects in it. This requires children with sensory defensiveness to press their hands into the styrofoam to find the object. Items you could bury in the styrofoam balls include paper clips, erasers, individually wrapped candy and stickers. If the children are allowed to keep what they find they will get excited about the activity and will be more willing to try it.