In case you haven't gotten it down its like this.
Step 1: You do some ulis to engorge the top part of the shaft (as far as I understand you pretty much need to have maximum engorgement for any variant of erect stretches) then you push in deep with the uli hand to try and grip some internal penis.
Step 2: Take your overhand grip to the tunica below the corona, and pull both hands outward.
This exercise feels different than a regular uli, in that with a uli you will feel the shaft expanded out the sides. With this one it expands both to the sides, and throughout the length of the shaft. It's a peculiar feeling you'll probably recognize it when you do one.