Hi Kooster,
I have one of the finger grip chisels. At the time it sounded neat. Now, I don't use it much. It works very well. You can cut grooves as a recess or as a raised effect by cutting the grooves and then turning the blank a bit smaller on the ends of your grip cut. Plan ahead so you do not go below bushing size.
It works on flat surfaces as well as convex. Just rock it from side to side while cutting on the curved surface. You can also use this and continue cutting more grooves on down the line.
Sanding...Very carefully with small pieces of sandpaper folded and follow the shape of the beads. Just like sanding a much larger bead.
As for cutting too deep, Think three times, measure twice, cut once. If you cut too deep, you will have brass accents in the bottom of the grooves!
I have used this as an actual finger grip or moved on up the pen for an ornamental detail. You may want to finish with an oil finish or friction polish with all the grooves. With CA, Probably use thin only(as not to fill the grooves) and that sanding the CA would be a bear in the grooves.
Hope this helps