That is like saying, “What is wrong with using commercial bar soap?”
Many of us here on SMF started soaping and making other products because our skin cannot tolerate the ingredients in commercial soap. Like @earlene I also have trouble with strong smells, many of which trigger migraines. Not only must I avoid commercial hand soap, laundry detergent, and stain removers, I generally cannot use any commercial cleaning products, air fresheners, or the like. Many FOs and some EOs also trigger headaches for me, too.
Believe me, it would a lot easier to grab things off the shelf. That isn’t an option for me if I want to function. Plus there is the concern about the long-term toxicity and pollutants in many of these products.
It’s amazing how many homemade cleaners work as well as commercial ones, without all the nasty ingredients. Sadly, home made stain removers don’t work as well for me, but they are my only option.
