Sea onion sweetened with honey has been used as a diruetic and an expectorant. Homer wrote about it. And Dioscorides, a Greek army surgeon of the first century BC, also wrote about it.
I, however, learned about it in Rough Medicine: Surgeons at Sea in the Age of Sail, a fascinating, well-written book I picked up at the library.
It’s something Dielli would have known, a common remedy where she was from.