Has anyone tried these?

That is an idea of Don Norris's. He is a cranky decent person and he does quality work.
Those wraps work well, and they serve a purpose. They make a nice wrap for a random stone.
You can make them yourself. Get .051 sterling wire. cut two lengths of wire each fitting around a portion of the stone plus. Cut a center wire. On the center wire make a loop about 3/8 of an inch in diameter and solder with a small chip of medium solder. Solder the two loops to the main wire, one going up, one going down.
Soak the finished work in pool acid and polish with a felt wheel with Zam!.
Place the stone on the loops bend them over where they go, and take Duck Bill pliers and roll the wire in a circle untill the wire tightens up on the stone. Twist the attachment loop untill it is in the right direction for a necklace, broach, etc. There she be. Simple, effective and doesn't detract from the view of the stone.

I called Don about three years ago on his cell phone. He was in a Denny's eating breakfast and yelling at everybody, started yelling at me, and started choking.
His wraps look great however! I suppose tis the price of quality. The wraps use a single hanger wire, .051, and the two loops attach to it.
I make similiar ones using square wire and I like it better. I twist the wire, and it adds a fancy touch to it. They are very easy to do and install the stone. I can make for us but my prices will be the same as Don's. I highly reccomend Don. His work is absolute top shelf and worth it. He has a silversmithing course that is very well detailed and will bring a newbie to being a silversmith. He knows his stuff.
He is like a lot of older people I know of. He barks but when you love what you do, and it is like theirs they bend over backwards to help out.
He is actually pretty funny at times.

I can walk you into beginning silversmithing. It takes desire. Want power is a very energizing force. I also posted a thread on silversmithing early in the forum.
If I can do it, so can you.

Krazy, just get a scrap piece of 2 X 8, or 2 X 10, some scrap silver wire, a propane torch, Ace Hardware, or Walmart, or Home Depot. About 14$. Some infamous borax. Put the piece of scrap silver on the 2 X 8, light the torch. Turn the torch upside down to heat the silver. It will flame harder. Watch for the heavy flame and it blowing itself out. Focus the flame on the silver wire. Watch the glow of the wire. Let the wood smoke, it will burn itself out. The silver wire will glow red, then retract into itself into a ball. Sprinkle a little borax on the ball of silver. Put the ball into a container of pool acid, once again, Ace Hardware, Walmart, Home Depot, etc. You now have a silver ball to be used on a ring, pendant, etc. Melt all the pieces of scrap untill you can control the melt.
You are half way to being a silversmith.