There are two reasons to eschew store-bought detergent for the homemade variety. First off, DIY detergent costs next to nothing, which means there's a financial incentive. There's a health incentive, too; making your own gives you full control over the ingredients used. A simple recipe involves nothing more than bar soap, washing soda (sodium carbonate), and borax—the latter of which kills mold and mildew. Click here to get step-by-step instructions.