I've never had it, because I've had my brows permanently shaped with laser hair removal (so glad I did that particular procedure), but my salon does it. They say you don't run the risk of burning, ripping or stretching the skin. They remove the stray hairs by wrapping them with thread (sorry never seen it done, but it involves multiple wrapping somehow, tangling the hairs into the threads). It's a very old techinque from somewhere, don't remember where, but it's been used for centuries. I know it takes some skill. It's very trendy right now.