I have a set on a flemish string; did't put them thru the twists, nor tie above or below... tied them onto the string in the center (think I cut one in half, placed one on either side of the string, and tied.)
I can move them easily up or down the string, yet they stay where I put 'em unless I move 'em intentionally. Helpful in finding the optimal placement.
They made a little more compact ball, which I later trimmed down to sort of a cylinder shape - my Thunderstick is very quiet with less than a full set. VERY pleased with them, by the way.Excellent quality, very effective, and easy to get.