Eight sets a day is a lot, but splitting them between two positions lessens the effectiveness.
Hobby has given you good advice about hanging to the side. Like you, my first six months of hanging were practically unproductive. I was discouraged because I was hanging totally in the BTC position with little results. Then I tried something different. I hung Under the Leg.
UTL gave me an intense stretch. A couple of sets of UTLs followed by BTC would make the BTC sets feel totally different. Fatigue was almost instantaneous. Bib explains why this happens:
The ligs vary in toughness. You may have several short, but thin fibers, which are easily broken and/or stretched. This will give fast gains. Or you may have short thick fibers, which are hard to break or stretch immediately (tough gainers). Once these short thick fibers are broken, gains may be easy. Then later, the longer fibers come into play. Or I should say, as the shorter ones are broken or stretched, the longer ones increasingly come into play. As time goes on, more and more fibers are involved at the same time during the stretch. Short ones break or stretch, and the next shortest take more of the load. This is why gains eventually slow down for everyone.
This is also one reason why it takes increasingly higher weights to achieve gains. It is also why some people talk about the ligs becoming tougher. They are somewhat tougher, because they become thicker as they heal. But more than that, each fiber becomes more equal with the other fibers as time goes on, they increasingly resist the stretch in harmony. Then, one must become more refined in his attack. Vary the angles even more. For example: After hanging for several months, a good stress is to hang under each leg, over the side edge of the chair, while seated in an almost BTC position. This greatly stresses each SIDE of the ligament bundle, dividing and conquering. Then, a normal BTC hang will stress the middle of the bundle. The sides are already longer from the side stretch. So the middle then has to take the load. This is just one example.
Recently, I have switched my hanging angle to SD. At this angle, I was getting an excellent stretch and obvious increases in my flaccid stretch. After a couple of weeks, the feeling of effectiveness wore off and I found myself increasing the weight dramatically — to 27lbs! Then I remembered hanging to one side. Hanging to the side is very similar to the swinging of weight you had mentioned, ModMan. The swing focuses extra stress on one side, or area, of lig bundles.
I tried leaning to one side as I hung SD. It’s not a very comfortable position; I’m already sitting at the edge of a chair and I lean over at about a 45-degree angle. To support myself, I use another chair beside me to lean on. The stretch is intense. Even if I only hold the side position for 2-3 minutes/side each set, it has a tremendous effect on fatigue and lig soreness.
Andrew and Hobby have the right idea, and so do you (sort of) with the swinging: concentrate the stress into a more localized area.