This tutorial shows a method of installing "keepers" foot braces in a skin on frame kayak. This method is with screws. Although for us it is the only metallic parts on the boat, we find it practical, quick, and easy replacement. Of course you can lash them if you desire. We have never seen these foot braces fail ever. Also we have never seen them jam or foul from sand or debris.
These foot braces can be purchased from The Skin Boat Store-  shop.skinboats.com  and do come with the necessary fasteners for this method.