SAGE: Periodically wax the ferrules (where the rod pieces separate) lightly with paraffin to ensure a firm fit and proper function.
http://www.sageflyfish.com/equipment-care.html
Orvis includes ferrule wax with each rod purchase and the booklet that comes with each rod recommends using ferrule wax:
http://www.orvis.com/store/product.aspx?pf_id=9G97
I've been using paraffin wax on my rod ferrules for decades and I have never had a ferrule stick or come apart on any of my rods. I've seen many, many, many rods come in for repair when the owner tries to remove stuck sections or when their rod comes apart during fishing. I have never received a rod for repair because of grit or dirt wearing out the ferrule, but it is a good practice to take care of your rod, put it in a case and sock and keep it clean and free of grit, sand or dirt.
Note: Do not use wax on the metal ferrules found on bamboo rods.