I would question based on those charts posted, what does it look like when the spiral is not working? I imagine if you add a random number into the equation it will also look like it is working because working is based on a visual test and not working is left completely open ended.
Assuming "not working" means it gives a signal that results in a losing trade, you would have a loss. For example, On the above chart, if you entered when the high of the bar after the bar with the triangle was exceeded, the trade would likely have lost money. Sometimes the potential signal would not result in an entry. For example if you entered with a sell stop with this or for a buy stop limit with this
Years ago measured in decades, French Curves were used as a fringe-form of TA. From time to time, I've done cursory searches, but can not find direct usage info or details for capital markets. "A French curve is a template usually made from metal, wood or plastic composed of many different segments of the Euler spiral (aka the clothoid curve). It is used in manual drafting and in fashion design to draw smooth curves of varying radii. The curve is placed on the drawing material, and a pencil, knife or other implement is traced around its curves to produce the desired result. They were invented by the German mathematician Ludwig Burmester and are also known as Burmester (curve) set." https://en.wikipedia.org/wiki/French_curve
Science (Physics) and Mysticism all converge when the Unity of the Quest for Ultimate Reality permits.
%% LOL%% ; thats like the guy that shot many cans , then drew his circle target afterwards. It works even better in hindsight.........................
I use the concepts contained in the mathematics of the Spirals for years in my trading of the Futures contracts. Thanks to @ph1l for posting this thread and I am surprised that it has not received more posts as it is an important and valuable tool. https://en.wikipedia.org/wiki/Golden_spiral