>>2952607
> anyone used this before? yay or nay?
No, but it looks expensive and a bit inflexible (can't move it).

>the traditional ones that you hammer up dont work for me, bench underside is not acessible
Make the hole wide enough and you'll be able to pull them out easily from the top. Can be a bit fiddly with the spring ones, though. Also, there are hat shaped bench dogs that won't ever get stuck because you can drill generous holes as long as they're smaller than the "brim" disk. Hell, I've used M20 bolts with two nuts on it as a substitute for these and it works just as well. As for "muh metal": just make sure the dogs are just half the height of the work. If the work really is that thin use an equally thin piece of scrap with thicc wooden dowels drilled through it for bracing against the dog holes.