Most guy's, I've seen, will do that exercise sitting down, using a lower floor pulley lat machine. Bracing the legs gives better support to the working back, from that sitting position.. Some will use a curl grip (fingers under the bar..rather that over). The full extended arms give that better over all over stretch. Some of these older exercises, like this exercise, seem to fall out of fashion for what ever reason. Still a very good BBíng movement, hopefully making a come back. Hanging from a overhead bar, with the fingers interlocked, gives a great stretch to the lats and shoulder girdle. If there is any secret to stretching it would be relaxing the body during the stretch.
Don't see many guy's doing lat stretches much anymore. Like bending at a 90 degree angle, graping an solid object (pole, rack, etc) and pulling and stretching the lats. Either both arms or one arm at a time. Stretching the lats ( like for the hams & calves) seems to have a good affect in increasing the lat size (influence on the muscle tissue, etc). Gymnast spend a good amount of time stretching he upper body/lats before any serious training periods...exceptional backs, yes indeed.. Good Luck.