Very creative and nice looking too.

I do want to warn you that most normal key ring rings do not hold up well. Thats what I use for my dogs tags, instead of the s-hooks. A few times over the years,my mother or friend or I have hooked her leash to them by accident & they broke as soon as Raustyk or Nanook started to pull. They don't hold up well at all.
You can however buy similar clasps (like the squarer one on that collar & other shapes) in most hardware stores for usually 50 cents to a dollar or so and they are more durable.

You may want to test it out in your yard. Or if your dogs have a good recall test it at the park, just please bring an extra collar just in case.