DO NOT USE ANY LOOSE SUBSTRATES IN YOUR DRAGON'S TANK!!!
It's totally unnatural for them, as you saw in the photo, the Australian Deserts that they come from are not the same deserts full of sand that we think of over in the US, they live on a hard, rocky terrain with vegetation, so he has no concept of living on a loose substrate, and he will eat it. He already ate paper towels, what do you think he'll do with a loose substrate?
Here's the other issue, beside the fact that they lick everything, and a bowel impaction in a young baby is usually fatal: All loose substrates, whether sand, crushed walnut shells, wood chips, bark, seeds, coco fiber, etc., doesn't matter, they all harbor and breed all types of bacteria, fungi, and parasites from the moment you put them in the tank.
Dragons are very prone to developing skin/scale infections, eye infections, and a lot of Upper Respiratory Infections, and if you put a loose substrate in his tank, you are putting him at an unnecessary risk for serious infections all the time. Breathing the dust from sand or the like often causes constant/chronic Upper Respiratory Infections. So why do this, what is the point of taking such an unnecessary risk?
Then there are the Calcium/Reptile sands that turn into hard, cement rocks as soon as they get wet, and these kill more baby and juvenile Dragons than anything else, along with the horrid and lethal Crushed Walnut Shell Substrates.
Bottom line is that if you have a Bearded Dragon you need to have only Solid Substrates. Your best choices are the stick-on, textured, slate tiles you can buy at Lowes and Home Depot (easy to clean up on the spot, and keep their toenails trimmed), non-adhesive shelf liner, Reptile Carpeting, etc.