What is this form of active breathwork?

Apologies if this is not the correct forum for this question.

Some time ago, I learned a form of breathwork meditation and I would love to know what it is and where it comes from. The person I learned it from called it a 'booster' and he picked it up in California in the late 60s or early 70s, but I have no further information than that.

• Start in a kneeling position, quietly
• Om, visualizing a bright light like the sun above your head
• Place hands in a triangle on the floor, breath in visualizing the light filling your lungs and bend to the floor blowing the light deep into the earth. Sit up (keeping hands on the floor) and breath in light again, big breath. Repeat this breath cycle 10 times with big breaths, light in, blowing down through hands into the earth
• On last breath take the biggest breath you can, and pulse it twice all the way out deep into the earth
• Take a breath and hold it (+/- mild valsalva) while standing up on your knees, reach overhead into the light, and pull it down through your body with your hands, only so fast as you can keep it in your fingers, and push it in a column straight through you deep into the core of the earth
• Keep holding
• Breath when you wish, or when you come back

If you do this, you should attempt it on a big bed or someplace with a lot of soft area to fall into. You can pass out hard. You may repeat several times, or just once.

I've found it a fast way to release the daily tension and enter a gentler, more meditative space very quickly.

Can anyone point me in the direction of where this comes from or what it is called? I would like to learn more about it.