The Main advantage to using the knotless knot for your hair rigs is that you can put your bait on the hair before tying the knot. That is helpful in creating just the right distance between your bait and the bend of the hook. What you do is cut of the length of line you are using to tie the leader, tie the granny knot that is your hair loop first. Then put your bait onto the loop; boilie, maize or whatever. Then follow the diagram below:

I use braided line such as powerpro or one of the sinking braids made by kryston for 90% of my leaders.

The "Knotless Knot"