Last week, the former welder presented to the world his latest creation — an upside down hair-washing machine.
The bizarre machine resembles somewhat of an inversion table used to cure joint and back pain, with a transparent tank fitted near the bottom.
Proceeding to give his viewers a personal demo, Geng clipped his nose and placed a plastic tube in his mouth to allow him to breathe underwater.
After flicking on a switch, the table slowly tilted backwards until his head was fitted into the tank.
After turning on a valve, water began to fill in the tank as a panel installed at the bottom started spinning, creating a current that ensured each strand was given a good wash.
The pamper routine is completed with a hair-drying system as well. After the water is drained from the tank, hot air would be emitted to give the user the perfect blow dry.
Geng Shuai, a 31-year-old DIY tinkerer from Baoding, Hebei province, has shot to fame for his "utterly useless" yet hilarious contraptions, including a meat cleaver smartphone case, a barbecue football table and an earthquake-proof noodle bowl.
Every country has its toolshed inventors. But China — which gave the world movable type printing, gunpowder and the compass — has spawned a population of tinkerers who display the kind of outsize ambition that has helped the country become a global economic giant.
Geng may now be the best-known among them — a new kind of social media star whose calling card is his quirkiness.
Geng is most proud of his hammer bag. It's a hollow steel mallet with a compartment that slides out of the head. Perfect, he says, for storing your phone, keys and wallet. It has a strap so it can hang over the wearer's shoulder.
His other inventions include a 66-cm long comb made out of iron, a metal contraption that makes flicking someone on the forehead more painful, and a toilet built into a scooter that flushes when you pull a lever on the handlebar.
"Most days I don't go to sleep until after midnight, I'm so busy thinking, OK, what should I make next?" said Geng, 31, who sports a ponytail and trademark blue dungarees.
Geng is part of an industry that generates as much as $4.7bn in revenue, and one that has few parallels outside of the country. In China, the most popular live streams are not of live events or the feeds of friends, but performances or shows held by strangers.
Geng tries to come up with a new invention every week and to make videos two or three times a week. He makes about $150 every time he does a live-streamed broadcast — decent money in a town where five people can have a lavish lunch for a total of $25. He makes enough to support his family — he and his wife have two children — and his brother, who shoots the videos.
Geng attributes his fame to China's rapid industrialization, which has seen millions of people migrate from rural regions to small apartments in the big cities, where they work long days.
"Chinese people love inventions and inventing stuff, but because of economic development, most people don't have the time to do it," he said. "That's why I am popular — they watch me making things because they can't make things themselves."