I'm aware that scraping your feet on the ground is not the same as a pedal strike...the later can be avoided by (1) shortening crank length, (2) raising the BB somehow, for instance using bigger tires, (3) not turning as sharply, (4) or by leaning your body more into the turn rather than the bike. Scraping your toes on the ground sounds like it relates more to bad bike posture. The suggestion of keeping your pedals level when turning is a very superficial proposal for what sounds like a more fundametal problem relating to bike fit and posture. Bike fit, particulalry saddle height and position, is something that should be reconsidered here, as well as how your foot is positioned on the pedal. If your saddle is positioned properly, I can't image that a normal person would have frequent toe-scraping issues even with the combination of a rather low BB and long cranks.