I heard in sacto, guys would use wood screws to hold in rails all the way through the deck, then hammer off the pointy end.....
Fairly common in general.
Others I know put the longer screws through the deck before they grip it and angle grind to tops off for a nice clean but well locked in.
Lock bolts or sex bolts are much harder to get and most people don't want a million things on the top of their boards.
I have seen some people put down double sided tape to lock the rails in place too, then screw them in.
Everyone can have their own deal with rails.
I prefer boards without rails, but I did use them when I was a kid and I can see the uses for them nowdays too.