Legacy soap could potentially be a soap that has been passed down through generations in a family for its unique properties. It might have been made from special ingredients that were locally sourced, like herbs or oils from a particular region. It could also be associated with certain cultural or religious practices where the use of this soap was considered important. Maybe it has a story of how it was made in a small, artisanal way in the past and now is facing challenges in the modern, mass - produced soap market.
I'm not sure specifically which 'legacy soap' you are referring to. It could be an old - fashioned type of soap with a long - standing brand or manufacturing process. Maybe it has a story related to a particular family - owned business that has been making it for generations, using traditional recipes and techniques.