Not seen those, but when my sashes are closed and locked, I added an extra security feature after hearing that the old sash locks could be opened.
I drilled a small hole through each top corner of the lower sash, and partway through the bottom corners of the upper sash--and put in masonry nails. I just pull them out a bit to open the windows during the day, and close the window and push the nails back in at night. They can't be seen from outside, and are barely visible from the inside.

Columbusguy1, that's essentially the kind of hole my windows have: through the upper corner of the lower sash, and then partway through the upper sash at two places, one for when it's completely locked and closed, and one for when it's about 3"-4" open. I was just hoping to find something slightly more attractive than nails to use with them, especially so as not to risk having any nails or pins drop to the floor and be chased around by the puppy :-)

"any nails or pins drop to the floor and be chased around by the puppy"

Dogs HATE picking up metal in their mouths.

My dog chews foil.

Yup, I've taken screws out of the mouth of the puppy in question.

Oh, yeah. Anything on the floor goes into the dogs mouth. Just managed to dig a screw out of her throat before she swallowed it! UGH!

With me, it's my siamese cats. They like to find things to chase around the floor--fortunately they don't eat them. My older one will knock small items off and then play with them, while the younger prefers to chase laser pointers.
When the nails are pushed in, they stick out about an 1/8", and are too high to reach by inquisitive paws.

You could try the chain idea with small dowels attached with screw eyes....

Training service dogs to pick up metal objects is one of the hardest thing.

Foil is soft enough they may chew, especially if it has food flavors on it.