We'll make it short today. You've probably seen those little packets of silica gel at some point. You know the ones. They're those little clear beads, they come packed with some sport of product or other, you're told they're 'non-toxic' and 'do not eat'.
Why don't you want to eat them? Because they absorb water. A lot of water. About 60% of their mass. There is a lot of saliva in your mouth. Do the math.
Here's what silica gel beads do in a glass of water:
And here is what happens if you try to eat the silica gel beads you are told to not eat: