I buried the ripcord so deep per a tutorial I saw on youtube. Going a little more shallow seems to help. I'm using a very thin whipping twine that's almost like a tiny ribbon. The zing-it didn't work at all.
I was really hoping that the whipping twine buried in the knot, being completely unattached to either rope, would be the answer. No luck.
DemostiX, how do you attach your leash? Is the thread difficult to grip? Do you ever have any failures?