I think I might try this when I get home! For those interested how it works, if I remember my chemistry correctly (and I probably don't it was years ago
) then the soap is reducing the surface tension of the water. Something called Marangoni's effect (I think) in the case of a gradient of surface tension from one zone of liquid to another, there should be a flow from the low surface tension to the high surface tension and that's why the pepper gets pushed to the side!
