I have a solid core door as my workbench top, and trying to use reg. dogs is a pain. See pic 3. I first have to make a sleeve of oak, 1 1-4" in dia. and then drill a 3/4" hole in it, then glue it in place. Pain in the ass.
I have some sailmaking awls that I use. See pic 3. I took them to the bandsaw and did some modifications to them. See pic 2. As of now I have a plastic tab, that sticks out of the top 7/16" of an inch.
Now all I have to do is drill a 4mm. hole anywhere on my bench and I will have a Bench Dog.
The awls I have used for years in both sailmaking for 30 years, and in woodworking and never broken one nor bent one.
The awls I use are made by C.S. Osborne & Co. and should be available at sailmakers and leather shops.
I hope this gives you guys some ideas for use and improvement of the idea.
By the way I am sure the 4mm. holes will be filled with sawdust but can be easily reamed out with a small drill.
Tor and Odin are the greatest of gods.