When I first started, I found that my drilling was too casual, and I needed to put some glue on the stud before screwing the metal stopper onto the turned top. I usually used polyurethane glue. But as I learned what I was doing, the drilling/tapping got better, and today I prefer to not glue them together.
I haven't made any of the dowel/silicone variety yet. But I do have one that my wife bought at a craft sale many years ago. The actual user experience is that the silicone condom does want to work its way off, and applying a bit of glue would make sense.