How well does the abs bleed/refill "joyride on gravel" work? Where does it bleed into?
The joy ride does nothing to "bleed" the system. The joy ride will cause the ABS system to react, operate the brake fluid pump, and move the "stale" brake fluid out of the ABS fluid passages so it is replaced with fresh, hopefully less moist, new fluid.
A joy ride can work. How much the fluid gets moved around within the system depends on how much the ABS system is called upon to operate during the driving.
I wouldn't drink even one drop of alcohol prior to the joy ride. A police officer is more likely to believe a "I was just trying to fix my Sprinter brakes" story if you don't smell like a brewery. Have fun. vic