How do they make Curly Bamboo?

I like those curly bamboo plants but they charge like $20 for them. I grew up with bamboo and realize it is REALLY easy to grow so I got the bright idea that I could go to the flea market and get bamboo for like a dollar and curl my own but I am not sure how to go about it. There are new shoots on top but how do I keep it curled to grow that way?

From this site:


How to make Curly Bamboo?

When you see curly bamboo, you may think the fancy curls and wavy style grow originally. Actually, Lucky Bamboo only grows straight. To make them curly, growers have to lay them on a huge long table in the house with hot temperature, cover 3 sides, leave one side to the light and let them grow naturally towards the light, then manually rotate them periodically to make the curly shape. It takes an average of one and a half years to make one wave.