All you need is shaving cream and cornstarch. I mixed equal parts into our sensory bin and squished it all together. The more it is mixed, the "less messy" it becomes (sort of, depending on your definition of "messy"). When the cornstarch is mixed throughout, it does keep the shaving cream from covering your hands...but we still were pretty covered after playing for a few minutes. LB enjoyed making a "snowman" and dropping balls of the fluffy stuff, but she did not love when it came out of the box onto her toes.
And, when your Little Bear decides she is done, be fast, mommy. Scoop her up before she goes running through the kitchen, into the dining room, and up the stairs to take a bath. Because she's covered in the stuff, and she will cover your house with it too.
As for clean-up, I found it helpful to put a large sheet underneath the sensory bin and just roll it up and throw it in the washer afterwards. I covered the bin, thinking maybe we'll use it again tomorrow, outside this time! We cleaned LB up in the bath tub, and, as for the fluffy stuff that she spread throughout the house, well, it swept up quite easily with a broom.
