Source:
https://scmp.com/magazines/hk-magazine/article/2037595/salty-wetHK Magazine
Salty Wet
吹水 (chui sui), v. Cantonese slang. To chat, bullshit.
“Lecherous.”
Said to originate from the fact that the dockworkers of Shek Tong Tsui would frequent the area’s brothels after a hard day’s work, and their sweat would be both salty and wet.