>I was wondering how long do you hold the stretch for in the V stretch? <
That can vary. 7up the guy who developed them used to hold for a few seconds and them move his fulcrum point and hold for a few seconds again. Since then they’ve gone in various directions. If you are trying to impact the tunica its definately worth considering longer long stretches, maybe 3 - 5 minutes, in a kind of emulation of hanging. If your LOT is high you can probably gain through the ligs and these are easier to pull so shorter, less intense stretches should do the trick.
>Also I gather from the video that the DLD stretch is basically like doing a kegal with your flacid penis being pulled outward, no? <
DLD had a stretch routine consisting of simple stretches, V-stretches and kegels which he called the DLD Blaster. The video is in the Tutorials forum in the Gandalf video series thread.