Design student, Aaron Mickelson, proposed the idea of packaging that disappears.
He predicts that “if companies created disappearing packaging for popular products, America could cut down on the 140 billion pounds of wasted packaging generated every year.”
One idea is Water-soluble soap boxes. The idea is that if the customer takes the soap box (with the soap) into the shower, it will dissolve.
It is estimated that “Nivea's Milk Bar wastes 7 grams of paper per package. This results in 3,950 pounds of waste per shipping truck!”
More about his ideas on packaging that disappears with examples are given here - https://disappearingpackage.com/