– How high in the fabric are they? Generally the weight of the tails will pull the loop out and it drops free. Doing this skill without much height will make it more difficult for the fabrics to fall away and apart. I generally have a large pool of fabric on the floor with my rigging and the weight of the tails helps it all fall apart.
– Are the silks sticky from rosin or humidity, causing them to stick together?
– How much fabric / tail is left hanging beneath the split? Ample tail weight will help the knot fall out – this is kind of piggy-backing on my first bullet.