String wax is something that I think gets used wrong by alot of people. It is just that, STRING wax, not rail wax. I myself don't exactly see what it does to the string. The only thing I think it does is keep the string "hydrated" and not drying out and fraying and such. Also alot of guys put string wax on there center serving. As they shoot the bow wax can come off and get into the trigger mech and cause problems, Horton used to put a warning on the wax telling you not to use it on the center serving. I do not know if they still do since my last stick of wax was from wal-mart. So if you was to skimp on the wax, I would say it would not be life or death right away. But the rail lube is a must or you will ruin your serving alot faster. It also cuts down on drag with the rail and will add a few FPS.