NEVER NEVER NEVER NEVER use a choke!!! If you want something like that use a pinch or a prong. Studies show that before the dog responds to the pressure from a choke it can seriously hurt thier trachea or even collapse it! Some dogs just dont stop pulling until they have no choice and thats where it gets dangerous. Pinches/Prongs give and immediate signal by pinching the skin which is more effective and faster that pressure and choking. Please for the sake of the dog don't use chokes
I've never tried a martingale, but i have heard good things about them.
If that still doesn't work try a head collar, The gentle leader harness has worked beautifully on my bp