Meanwhile, Ma, Duan, and pop singer Shangguan Xi'ai paid a visit to the Mausoleum Park of Sui Emperor Yang Guang, who started the construction of the Beijing-Hangzhou section of the Grand Canal.

The trio also visited a beauty salon for a traditional local shave. The barber began by shaving from the right side of the neck with gentle strokes, then moved to the left side of the neck, before moving the blade to the forehead, eyebrows, cheeks, carefully and gently removing facial hair, ear fuzz, dead skin, and stubble left by hair clippers, in a series of 72 strokes.

In the end, the barber lightly ran the blade along the bridge of the nose to complete half the stroke, known as the "72 and a half stroke", leaving clients feeling refreshed.

That night, the two groups gathered to share their experiences and discuss the history behind their discoveries.

Zhou states that the advancement of Yangzhou's service industry was closely related to the Grand Canal.

"For instance, public bathhouses were set up for laborers," he says. Yangzhou was once a prosperous gathering place for salt merchants during the Ming and Qing dynasties (1368-1911) due to its transportation facilities.

"There were many laborers, especially those working in the salt fields, who needed to relax and recover their strength at the bathhouses after a hard day's work carrying salt," Zhou says.