But, frankly, we just need to take a deep breath, get out some newspaper and dive in!
Messy play, or what many therapists and teachers out there call "sensory play" is an extremely important thing to explore when it comes to development. It allows for another modality for your children to discover and find ways to express themselves. It also isn't uncommon for children to be hesitant with messy play because they don't like to get dirty or the texture of the substance may turn them off. It is for these children that messy play is most important. You'll just handle their anxiety and/or aversion with sensitivity - introducing materials slowly, letting them start by just touching it with a spoon or even giving them some rubber gloves to wear while exploring.
So, today's activity is.... making "Goop." I know. It sounds disgusting, but don't be scared. I have found and tried out a ton of recipes, and this is the easiest to clean-up. All you need is some cornstarch and water. You can add some food coloring, if you like.
Begin by putting a good amount of cornstarch in a bowl. Let your child touch the cornstarch on its own - talk about what it feels like and predict how adding water will change how it feels. Then, slowly add some water little by little. At the right consistency, the "goop" will be drippy, but not watery. Your child will be able to pick up a little ball of "goop" and watch it melt before her eyes. If you don't mind the dye-factor, include your child's choice of color.
Encourage your child to become symbolic with the "goop." In this play, Buzz Lightyear jumped in the pea soup.
Now, I know this looks like it will be a pain to clean up. It really isn't. When the mixture dries, it turns to powder that is easily wiped off clothing and swept up. To get the toys and materials clean, just rinse and wash. I would suggest not wearing black, only because, like all white powder on black, it doesn't entirely wipe off without a trace - you'll need to wash it out.
Enjoy your "goop!"