Gravity brake bleed not working

My wife once fell asleep in the car while bleeding brakes! "Sweetheart, ok push the pedal down and hold it." (pause, silence) "Did you push it down?" (no response) "Are you ok?" (more silence).

Then we hear Sister Mary Elephant's voice "WAKE UP!!!"

To this day, she HATES to help bleed brakes and bribery of some form is required!! (C'mon, you know I'm not the only one...!!)