I thought this looked interesting how he did it. He kept some fluid in the bottom of the container, so air wouldnt go backwards.

But If I was to try this, I would raise the glass container above the bleeder valve. That way if it the tube was not sealed around the valve, then air would go out toward the container rather than into the hydraulics.

What say you?

 

Doesn't matter where the level of the container would be, if there isn't a good seal around the bleeder valve, air will be pulled into the caliper when the pedal is released and the system creates a vacuum effect. Actually, have used this system many times in the past if no one was available to help bleed the brakes, works great and have never used a sealer/grease around the bleeder threads and no problems.