From the Uli link:
Quote
3) Beginning at the base of your penis shaft, still while in a semi-erect state,
encircle the shaft in a tight OK finger grip and move your “finger ring” towards
the meatus, engorging the shaft and the penis head. Squeeze 5 times, let up
the pressure, and repeat this routine 10 times.
That is basically the Uli. I would add that it is important to kegel, then tighten your grip at the base and then slide forward to create great pressure in the distal part of the penis shaft and head. I think you may find it more beneficial to push toward the head, rather than just squeeze, to intensify the pressure.
I agree the Horse description isn’t very good. It is similar to the Uli, in that you clamp the base, but then you use your second hand, and make a ring with your fingers, and push that ring over your head, while your base hand is moving toward your head. So your two hands are moving toward each other, creating great pressure in between them.
If you have been doing regular jelks with progressive intensity for the last 5 months, you are probably conditioned enough to try these exercises, but start slow. They both can generate a lot of pressure. Gradually increase the amount of pressure and time.