How it started
History of Drāno
Mrs. Drackett, who for years effectively served as the company's front office, is credited with naming the company's first major consumer-product breakthrough in 1923. An English purist, she insisted on using a macron - a small dash - above the a to ensure the correct pronunciation of Drāno and leave no doubt as to its intended purpose.
From Wikipedia’s article on Drackett, shared under CC BY-SA 4.0.2