I now have more information on insta-snow. I had a mishap with it that you can read about here. Anyhow, if you add water to it after it is initially activated the water won't be absorbed. Instead it turns into the cream of wheat disgusting stuff I had the other day. So that was my bad. I thought after the water evaporated I could add more water with no problem.
If by chance you or someone you love does add more water to the insta-snow, you can let it dry. It turns into a thin film that easily comes off any hard surface. Note, I have not tried this with carpet, I'm afraid to! If anyone has any experience with carpet I'd love to hear from them.
To sterilize insta-snow you can microwave it for a minute. According to Southpaw Enterprises this should kill about 75% of the germs. Good to know if you use it in a classroom. I tried this and the insta-snow came out fine and didn't lose its texture.
If you don't add extra water and let the insta-snow dry it turns back into a grainy substance that is easy to clean up. I found that wiping it up with a dry cloth or sweeping it up off the floor is much easier than using a mop or a wet sponge.
If you want to try insta-snow or buy other cool autism materials visit National Autism Resources.