Researchers hypothesize that baby shampoo could reduce the amount of coronavirus that infected patients spread to others. Small amounts of baby shampoo in saline rinses have been shown effective in decreasing the shedding of other viruses and clearing the sinonasal cavity.
A study published in the Journal of Medical Virology in September 2020 found that baby shampoo, as well as certain other oral and nasal rinses, has the ability to neutralize human coronaviruses. Though the researchers did not use SARS‐CoV‐2, the virus that causes COVID-19, they used HCoV‐229e, another human coronavirus that is used as a common surrogate for the former. With contact times of one and two minutes, “1% baby shampoo solution was able to inactivate more than 99% and more than 99.9% or more of the virus, respectively.”