Share some Pictures next time you make one that way Fritz. It sounds interesting!
I have forgotten my jig when I was running an 'archery repair' night but found that one can make twisted loop flemish strings without it. We wrapped the strings around two chair backs to get the proper length (bow length + about 10 inches per end) and used scissors to nip 1/2 inches off creating that frayed end which allows the bundle to fade into the string rather than leave a clump.
It worked better than I thought and we had several loaner bows up and ready by that evening.
When teaching new string makers I give them a mnemonic that helps me remember which way I'm going. "Twist away, fold back."
I do advise new stringmakers to use two different colors. It's much easier to match which bundle is which when weaving the ends back in to form the loop and this is one thing that can make your string fail if you get it wrong......and they're pretty! Baronial or Kingdom colors if you're using the Dacron make a nice touch to your loaner gear. Black stays looking nicer than white due to the dust and stuff the wax picks up, but a red/white striped 'candycane' string is almost worth remaking occasionally for the kids.
Ladies can also use this twist for their hair with a long scarf. Split hair in half, drape scarf on neck, lean forward. Starting at the nape of the neck and working toward the temple on each side fold hair around scarf until the temple is reached. Now separate scarf from hair and 'Flemish Twist'. Twist the other side of the hair in reverse. Cross the two, Making sure the 'rope' is laid on the downhill side of the roll that's attached to your head. Wrap the finished 'ropes' around and tie them in the back. No pins are needed, if done properly it will last all day. It's great for keeping that lovely hair out of the way of your bow's string, is cool for summmer, makes a good foundation for a hat or something to pin your veil to without killing your scalp. Gentlemen need not wait for your maid to braid your locks for 3 hours as it can be done in 3 minutes or less with practice!