BUMP
Rosary Workshop - Knotted Cord Rosaries & Chaplets
"If you are interested in making mission rosaries or want to make rosaries to share with friends, consider the knotted cord rosary or chaplet. This technique of prayer counting is one of the very first ever used by the early fathers of the church."
"Knotted cord rosaries were issued in Viet Nam to various members of our armed forces. Chaplains would give knotted khaki cord rosaries to the troops to carry into battle. We also heard that they were worn around the neck and smuggled into countries where the church was not allowed. They were safe as metal detectors would not pick them up."
While the site linked above has directions for knotted cord rosaries, these instructions seem clearer to me.
And a Web site devoted to making and giving away knotted cord rosaries: Rosary Army