Here it is – mane puller, regular yarn, and a rubber band as scale. Sorry this was taken on my tack room floor at 9 PM, lol! The very thin black lines are horse hairs…
I have had zero issue with the braids not holding. Here’s what I do: section the mane into 8-10 braids, each the length of the metal on a mane pulling comb.
Fasten with a rubber band, and tuck the loose ends under the braid by folding the braided section back and rubber banding. It’ll make a “knob” end.
With a plastic needle, thread wax thread through the eye. I make each wax length about 8 inches.
Take braid and tightly roll it under itself until it rests against the crest of the neck (alternatively: fold braid twice)
With plastic needle and thread, pull through the rubber band section of the braid (takes feel), sew back and forth a few times (I do four times)
Cut loose ends
With this method you don’t need to tie anything, and unbraiding with a seam ripper is a charm. Sewing the wax thread through the rubber bands holds the braid tight.
This video is a pretty good loose example: