I think that was in the context of manual stretching. Dual fulcrum stretching or something like that. It was just another renaming of something else. If one fulcrum is good, “dual fulcrum” sounds extra super duper, especially when scrambling to come up with catchy names for one’s supposedly “new” exercises.
IMO, none of this hanging over a rod or stretching over a stick is truly “fulcrum” stretching or hanging. A fulcrum is the pivot point of a lever. The rod redirects force, but there is no mechanical advantage gained in this case, which I think the fulcrum term implies. I argued about this once long ago but gave up. Might as well call all this stuff fulcrum whatever because it has become the common terminology.
Glitzy sounding exercises such as “Single Short Momma’s Super Triple Fulcrum Testicle Tinglers” or such are usually retreads of old exercises or concepts. The new catchy name is promoted to boost the poster’s recognition and/or sales.
Back on subject and to the original poster: keep your sets short to start with, 10-15 min. When going over 10 min., check often for any loss of sensitivity. Monitor closely, especially when you start out and when moving up in weight. It’s possible to go from perfectly fine to almost completely numb within the span of only a couple minutes, so watch it especially toward the end of your sets.
If fulcrum hanging twisted (hanger/penis assembly turned 90 degrees or more to the side over the rod) limit sets to 10 minutes. Again, touch the head and shaft to monitor sensitivity regularly, which is a good habit to be in no matter which position you hang.
As always, start with light weight and slowly work up. Don’t push it too hard at first.