I'm not sure what to tell you on what works best. I've done back braiding but it was several years ago. My friend that was in the Navy said they told him that three times back through was as strong as the rope / line they were spliceing i belive.
Maybe somebody that does it pretty regular will chine in because i do very little braiding anymore and it wasn't that much when i was braiding. Knothead or Megabite ( their the ones that i can thank of off hand ) over in the braiding section would be of more help on that than me.