They also have an activity called bubble mountain where you put drops of liquid dish soap in a bowl with water and and have them blow bubbles with the therapy type tubing straws. that helps the children that like to chew on things or picky eaters. I had my picky eater do that before eating a hot dog and he actually took a bite of the hot dog, he usually just eats the bun and leaves the hot dog :D

Hey, one more thing, we bought a bag of cheap straws and gave our son pudding and applesauce to eat with the straw. (Great sensory hard work sucking it up.)He loved just chewing on the straw and we could throw them away and they were cheap like a dollar a big bag of them. Good luck!

We bought clay at the dollar store and got a plastic container that was square and flat for each color. We put enough clay to make a smooth layer in the bottom and had him make his letters in the hard clay. It doesn't dry out and it is a good hard work activity digging your letter in the clay and then smoothing it out for a picture... You can snap the lid on to put it away. We collected children's toys...nubby little hand balls, some squishy with gel, fluid, stringy silicon or rubber, and made little rice bags out of a balloon or flour bags too. Our therapist got some rubber stretchy chord...just a strip of the exercise chord they use in therapy...also the oxygen tubes just a short strip is a great chewy thing...put a knot in it perhaps...make sure your child doesn't bite pieces and swallow etc. There are store bought toys like little pipes that have little baskets on the ends with little balls that float up when you blow in the pipe end. The activity is to sustain them in air and catch them again. This looks like an alligator with floating eyeballs. We put together a little bin with sensory toys. I also asked my therapist to look at catalogs of sensory toys and then went on line to get my own catalogs. Some of the home-made things were the most useful though. You may use snack foods like chewy and crunchy textures and sour and salty with chewy fruit pieces and crunchy/salty nuts, allergies considered, carrots and celery etc.
There are some books that I loved and I'm trying to think...I think they were called "The sensory child plays" and "The sensory child has fun!" but I am going to have to go look them up. You could probably google that and find them or walk through the book store and check the books on ASD's and Sensory processing disorder.

Have you thought about gross motor type sensory play? Trampoline, balance beam, exercise ball, you can get swings you can hang in a doorway, you can wrap him up kind if tight in a small blanket (with his head sticking out of course) which provides deep pressures and then rub various objects up and down the blanket, like a ball or a rolling pin or whatever you have around that doesn't have sharp corners. We used to call the blanket thing "being a hotdog" and the different objects we the toppings like ketchup and mustard.
A smaller thing you can do is take a coffee can with a plastic lid and cut a small slot in the top. Give your child pennies to push through the slot - it should be small enough to give plenty of resistance. An added benefit is if you make hime do it with just the thumb and first finger, its great fine motor exercise too. You can also get clothes pins from the dollar stir and have him use just thumb and first finger to clip them around the rim of the coffee can.

Corn starch and water.