2 cup regular ole' sand
9 x 12 baking dish
spray can of scotch guard
Spread the sand in the baking pan and bake for 1 hour to remove any moisture.
Remove sand from oven with hot pad.
Coat sand by spraying Scotch guard thoroughly on sand.
Shake the sand and spray some again.
Repeat until your can is empty.
After your coated sand is dry, pour it into a clear container with water and sculpt to your hearts content.
Be sure and pour from one container to another. They you will see that the sand in the water actually does remain dry.