Bill Houghton, Sebastopol, CA
I've used a similar process for installing glass retaining molding - although, pessimist that I am, I use small brass wood screws, so I can remove the molding more easily when the glass gets broken.
When I've pushed brads into molding like that, or into picture frames, I've used Channellock type pliers with masking tape to protect the finished surface. I can see what I'm doing with the pliers. Your clamp is a nice alternative.