Using it weekly can substitute for a weekly exfoliant regime.
Traditionally, sand from the banks of the river is used as an exfoliant when bathing (often in rainstorms, especially during the monsoon).
However, other research has shown that lactic and glycolic acids can indeed inhibit melanin production separate from their actions as an exfoliant on skin.
Perhaps the gas was combined with an exfoliant in order to harm the environment as well.
