Ludwick Marishane is the youngest person in South Africa to hold a patent. His invention? A “bath without water,” a lotion called DryBath.

In today’s talk, filmed during the Johannesburg stop of the TED2013 Talent Search, Marishane shares how this unusual product came to be. When he was 17, he was sunbathing with a few friends in his town, where the water and electricity supply is highly unpredictable. One of his friends said, “Man, why doesn’t someone invent something that you can just put on your skin and you don’t have to bathe?”

Marishane thought, “I would buy that.”

Marishane spent four years creating DryBath’s formulation, using his mobile phone to do online research about how to make a germicidal lotion. While the product was originally thought of as a convenience, he quickly realized that it could also ward off disease and even preventable blindness for people without access to clean water. Marishane typed a 40-page business plan — and submitted his patent application — all on the small screen of his mobile phone.

To hear more about how Marishane invented and marketed DryBath, listen to his charming and funny talk. Below, watch three more talks about washing.

Theresa Flores: Find a voice with soap
Theresa Flores didn’t have a word for what happened to her as a teenager. Now she does — human trafficking. In this talk from TEDxColumbus 2011, she shows how trafficking can happen to your average girl from the Michigan suburbs. She also shares how, when returning to a motel where she had been abused, she had an idea — putting an 800 number for the National Human Trafficking Hotline on the bars of soap in the bathroom. She gave this soap to motels for free in areas where trafficking is common, in hopes that girls like her would find it in the bathroom.

Joe Smith: How to use a paper towel
Think you know how to use a paper towel after washing your hands? Maybe not. In this talk from TEDxConcordiaUPortland, Joe Smith will inspire you to use a single paper towel for every hand wash, by shaking your hands 12 times and folding the paper towel in half to maximize absorbency. The end result? Saving 571,230,000 pounds of paper per year.

Renée Botta: Soap saves
About a million children die every year from preventable diarrhea simply because of lack of access to soap and water. In this talk from TEDxChange, Renee Botta tells the story of a young African woman who began making and selling liquid soap in her home. Could this public health problem be solved with solutions that also feed the local economy?