Once in a while i give the girls something really messy. In a book I read several months ago - art activities for toddlers and twos the authors described a recipe for white mud, using soap flakes, toilet paper and water. The first time I did it, I used too much soap, and Anjali got a mild rash. The second time we did it at IEP class. I was wiser this time, we used baby soap and the children had a good time. But some parents commented that it was a big waste of tissue paper which can be used for a perfectly good utilization. We tried is a couple more times - once in Romania- but the effect was never so great -primarily because of the guilt involved in wasting perfectly good tissue paper.
Recently, I found another good source of mush stuff - recycled junk mail and newspapers. The mud is, of course, not so white. But there are two things that make it desirable - 1. The mud, when thickened with a bit of flour, can be dried out to make clay and moulded into shapes (we have never gotten to this stage in our home because Sophia inevitably pees on the mud at some point and we have to throw the whole lot away). 2. it acheived the sensory experience of mud without the bother of dirt, or the bother of soap (we use flour instead which is safe on the skin) and the guilt of using something that can otherwise be more constructively used.
Here are some pictures of the kids in mud in front of our house. The tray of blue paint was there incase the girls wanted colorful mud - and they did.
And a short video. I think the girls are having fun. They work very quietly when exploring mud (note the part when the girls use the gate grills as a basketball hoop)