C SECTION abdominal ski prep

First, I am an OB nurse but many moons ago we took over doing our own cesarean sections and were taught by OR nurses what to do....

I distinctly remember that when doing a low transverse abdominal incision skin preparation, we were to prep the abdomen and legs in a horizontal on the patient's body (I mean same as transverse) beginning at the incision site and working upward (proximal to distal) on the abdomen then down each lower extremity (proximal to distal) all using separate scrub sponge and paint sponges with betadine... we switched to hibiclens instead of betadine also several years back for every patient's prep (still doing the blotting post scrub & post paint - aka not giving dry time as you would with chlorahexadine solution prep self load sponges on a prefilled stick). Now fast foward to present day, after a few year hiatus from the same unit... when I returned nurses were prepping the site for the low transverse abdominal incision in a horizontal fashion on the abdomen and a vertices fashion on the legs. I feel that completing a vertices preparation on the legs is bringing contaminate back closer to the incision site. We are still using hibiclens on every patient. I hope that I am making sense.... Anyway I can not find any hard evidence when doing searches for proper prep technique but I still feel that horizontal on the patient (transverse) is the safest prep style... I want to know what your institutions do and if anyone can give me hard evidence to their technique, that would be better... I am beginning to train new nurses and have been told that no one else has taught them the horizontal (transverse) prep style. Help!