Legal Considerations Regarding Ingredients in Selling Homemade Detergent

Who would know if you used store bought soap if you didn't tell them. It could be your 'secret ingredient'. I don't think you have to list the ingredients as long as people weren't going to eat it. I would think if you were going to manufacture it and sell it on the open market, it definitely would be against the law, but wouldn't think it mattered at craft fairs.