score:5
This attraction really has very very bad documentation. I would not blame your google skills for this. Unfortunately, the information is English is very bad, but not much better in German.
The problem is that some years ago, all the villages had their own websites with such information, and then closed them and consolidated all to the regional and national pages. In that process, a lot of information must have been lost.
I found this PDF dedicating a half-page to the trail, with unfortunately not much more information on it. Some more information was to be found on page 11 of this PDF here, where they mention that the path starts in Stechelberg. That village still has it's own website with a subsection dedicated to the trail. Those are also all in German however. This Google translation should be enough I hope. There is more information on site in pamphlets available. If you need more concrete information I would strongly suggest you call or email the tourist office that is listed on the website. I am sure they speak English well enough to answer the most important questions.
On top of that, I can strongly recommend you the website bergfex. They list the most famous trails in the area with GPS, height and more information.