How can I decide whether to use a homemade mixture or a commercially formulated cleaning product?

Considerations of safety and performance should come first when thinking about using homemade mixtures.
Know the Safety Guidelines
Commercially formulated cleaning products are tested, packaged and labeled in accordance with standards set by such government agencies as the Consumer Product Safety Commission and the Environmental Protection Agency. Besides directions on how to use and store the product, the label typically provides the consumer with instructions on how to treat accidental exposures. Precautions about mixing certain products together are also given when appropriate. Some labels carry disposal instructions. And toll-free phone numbers enable the consumer to get additional information from the manufacturer.
Such safety assurances may not exist for mix-at-home recipes. For example, while the effects of "alternative" ingredients are known for their intended exposures, there may not be information on unintended uses of these chemicals or their combination with other chemicals in homemade cleaning products. If the promoter of the recipe doesn't have this information, it's best to check with the manufacturers of the individual ingredients to see if they recommend the mixture.
With mix-at-home recipes, responsibility for product label information falls on the person following the recipe. That means that the consumer should prepare a label that includes the names and amounts of ingredients; emergency treatment guidelines; safety procedures for mixing, combining with other products, usage, etc.; and complete directions for use. Poison control centers have extensive data on commercially formulated cleaning products, but may have difficulty handling accidental exposures to homemade mixtures unless they have information on the formula.
One final word on safety: Some recipes suggest that boiling water be used in combination with "alternative" ingredients. The practice of carrying quantities of boiling water from one location to another in a home, especially a home with young children, raises serious safety concerns.
The Importance of Packaging
Manufacturers of cleaning products select packages that are designed to ensure safety and preserve the shelf life of their contents. With mix-at-home recipes, safe packaging is another responsibility for the consumer. Old food or beverage containers shouldn't be used, since the contents could be mistaken as edible by young children, the elderly and people with impaired vision. And empty cleaning product bottles could contain product residue that may react with the mixture. Plus, unless the original label were removed and replaced with the appropriate label, it wouldn't reflect accurate information about the mixture.
Performance Considerations
Commercially formulated cleaning product labels include directions for the right amount to use for maximum effectiveness. If this information isn't available on mix-at-home recipes, consumers may use more than is needed, increasing the chances for misuse or damage to the surface being cleaned. Less than the right amount means that the job will have to be repeated sooner than should be necessary.
Finally, food products such as mayonnaise or yogurt are sometimes recommended as "alternative" cleaners. These products may be harmful to wood surfaces if misused. In addition, food product residues left on surfaces can breed bacteria. Continued...