Я ведь дал ссылку на рецензию, там именно про "мыло", а не "суп".
She begins by talking about her life as a server at a fast-food franchise called Papa Song’s. Sonmi would awaken with her cloned sisters, recite the Six Catechisms at Matins, work 19-hour days serving and cleaning up after “pureblood” consumers, end the day with Vespers, consume something called Soap, which contains nutrients as well as amnesiads that deaden curiosity, and go back to sleep.Once more awakening before yellow-up, Sonmi explores the dinery and discofers Seer Rhee dead from a Soap overdose.
--- Добавлено ---
И термин "мыло" он не просто так, в книге это немаловажный элемент создания образа "корпоративного постапокалиптического рая":
Of all the stories in Cloud Atlas, this one is my favourite. So much is going on in terms of history, context, politics, and society, and it’s set against a highly believable futuristic backdrop and told in a modified form of evolved English. (For example, with the politcal prevalence of corporations in this “corpocracy,” many everyday objects are referred to by their once-trademarked names: people drive fords, download information on their sonys, wear nikes on their feet, watch disneys, and so forth.)
--- Добавлено ---
А в чем проблема собственно? Для питания клонов создается специальный раствор, который кроме поддержания жизнедеятельности оказывает и седативно-амнезийное воздействие на организм клона. Название препарата в точности отражает его сущность. Как по мне, все логично и понятно. В книге по крайне мере.