You MUST try this with kids, or without! I have seen several mentions of putting ivory soap in the microwave. It sounded ild and cool and not very messy, so I got some. Jess was having a rough night, so I thought it might distract her. She LOVES it even though she was only humoring me at first. You unwrap a bar of Ivory soap, put it in a large dish (we used a pasta bowl) and then you put it in the nukulator on high. I was glad we used half a bar at first because it blows up! Not as in explosion, as in whipped cream coming out of a can. I would actually use 1/4 of a bar at first, just to see how big it gets so you don't use too small a bowl. It took about 20 seconds to start expanding and then it just kept going. 1/4 of a bar filled most of a pasta bowl, so it gives lots to play with. It is not wet or slimy, but dry and silky feeling. We watched ours expand and even leaving it after it kept getting bigger didn't burn it. It just got hot. If you stop it right away it isn't too hot to touch. I stuck a finger in the second batch right as it got out of the microwave and it didn't even feel very hot. I have not figured out how to color it yet, but give me time. I can see making a melt and pour soap that looks like a cake or something and then using this to make whipped cream on it for gifts. Or maybe working super fast and pushing it into molds. The big wonderful thing is that it isn't wasted or ruined by this. You can still use it to clean whatever. In fact, if you use it for laundry soap it might dissolve faster for liquid versions and it sure would be easy to make into powder for powdered versions. I have not tried with other soaps, but from reading several websites, ivory is the brand that works for this, possibly because it is whipped with air during manufacturing (this is why it floats and others don't). If you try other soaps let me know. We don't really use bar soap, so I don't have others to try. This is a cool rainy day kid project, and also something to do to get kids to use soap more for the bath resistant years.