I've not tried it, but frankly I wouldn't spend the money for it. I found a better picture of it here
Weiss Walkie No-Pull Dog Leash | Rover In Clover - Unique Dog Supplies
It really isn't anything other than a leash with a fixed ring at the clip.
When I'm walking the shelter dogs and there isn't a no-pull harness handy I often do this with a regular leash and get a similar effect:
Clip your leash to the collar.
Position the collar so the leash clip is at the back of the neck.
Wrap the leash around the girth of the dog.
Bring the leash up the other side of the dog and wrap it once around itself right near the clip.
Same effect and no money spent.
If you are looking for a good no-pull harness, I suggest the Freedom Harness. It has a front attachment point and a rear attachment point. You can attach to one or both (with 2 leashes or a double ended leash). The rear attachment point does have a limited-slip element to it and does tighten some around the girth of the dog, providing a similar action as that of the Weiss but on a more versatile product.