What you need:
1 cup of maize corn flour
Half a cup of water
What you need to do:
Mix the corn flour and water thoroughly in the plastic container to make your instant quicksand. Slowly stir it with a spoon and you will see that the mixture will turn into liquid. If you increase your speed and stir the mixture quickly, the sand will become hard. When in liquid form, punch or poke the mixture quickly and watch how your hands disappear in the quicksand.
When water is added to the corn flour and stirred slowly, water molecules travel between the corn flour grains and the flour particles slip and slide over each other, making the sand liquid. When the sand is stirred quickly or when it’s punched or poked quickly, water doesn’t mix with the grains efficiently so the sand turns hard. This mechanism is similar to the way quick sand works.
Quick sand exists in the solid form, until a change in pressure or too much liquidity makes it lose its strength to hold weight, thus swallowing anything that steps into it in that moment.