Naga Sadhus or Hindu Holy men leave after taking a dip during the first "Shahi Snan" (grand bath) at “Kumbh Mela” or the Pitcher Festival, in Prayagraj, previously known as Allahabad, India, January 15, 2019. (Photo by Danish Siddiqui/Reuters)

This picture taken on February 16, 2017 in Fangshan village in China's coastal province Fujians, shows a villager performing the “eating flowers” ritual. Villagers in eastern China have a unique way of washing away the taint of evil spirits – by bathing in a shower of scorching sparks. (Photo by Johannes Eisele/AFP Photo)

A couple covered in mud wait for it to dry at the Salt-works lakes near the Black Sea town of Burgas in Bulgaria on July 25, 2019. Thousands of tourists visit the red salt lakes for mud baths, which are believed to help the healing of muscular disorders and rheumatism. (Photo by Nikolay Doychinov/AFP Photo)

Japanese team trains before the 6th FINA Synchronised Swimming World Trophy at the Water Cube on December 8, 2011 in Beijing, China. (Photo by Feng Li/Getty Images)

Japanese chorus girls appear to be drilling in military tactics atop their theater building as they perform salutes, June 30, 1937. The officer is from the Japanese regular army and says the girls display more rhythm in their drills than do the regular troops. (Photo by AP Photo)

Women jump into the water during a traditional New Year bath in the Adriatic sea in Portoroz, Slovenia on January 1, 2018. (Photo by Jure Makovec/AFP Photo)

From the waters edge a New York policeman urges two young children to put their bathing costumes back on. (Photo by Ed Clarity/Keystone/Getty Images). July 1949

A Japanese Ground Self-Defense Force Type 92 Mine sweeping vehicle fires a rocket behind a Type 74 armoured tank during an annual training session, which is based on a scenario to defend or retake islands in Japanese territory, near Mount Fuji at Higashifuji training field in Gotemba, west of Tokyo, August 18, 2015. (Photo by Yuya Shino/Reuters)