A story I heard about Barbara D coming into NYC is that she would bring a custom built midi pedalboard in a road case and would stick it under whatever Hammond she was offered for the gig. As most of you know stock Hammond pedals sound terrible and have no sustain thus no walking bass. The pedals got noticed at the customs inspection and they couldn't figure out what they were so they held them up and she had to cancel a concert. She is one of the best ever at pedals. Chester Thomson formerly of Tower of Power and now Santana is another master of kicking bass. Check out "Squib Cakes" by TOP where he takes over doing the bass line during his solo. An old schooler from Newark NJ and now in France is Rhoda Scott who plays pedals in high heels! Sold a B3 to a guy in the Netherlands who saw her play and wanted a rig just like hers. Trek II products in New Brunswick NJ makes lots of Hammond add ons including a killer string bass unit.
I played pedals for years on a customized B3 and loved it. As far as how to do it, you practice jumps of 3rds, 4ths and 5ths, and scales without looking down, tapping the sides of the black pedals (C#, F#) for orientation. It becomes automatic after a while. You need soft shoes to feel where you are. I never did two feet, just for one semester in college when I took classical organ lessons. Still have my Roland PK5's to mess with. Nothing like the control you have and just jamming with a good drummer can be addictive. I miss gigging like that.
Thanks for the clip