This weekend I’m at FOO East, a sort of “wiki-conference” where friends of O’Reilly meet and exchange ideas. This morning I made bath bombs with some lovely folks! We combined two parts baking soda to one part powdered citric acid, then spritzed it with witch hazel while stirring and fluffing vigorously. Then we added in some scents (I used peppermint oil) and packed the mixture (about the consistency of brown sugar) tightly into soap molds. With any luck, they’ll be dry by the middle of the afternoon tomorrow! If you’re looking to make your own, this Instructable is a great starting point.