Water, paraffin, non-sudsing surfactant and a big blender. Or water emulsion wax from your local janitorial supply if they still carry it. Military loved buffer marks, so we always had to use soft wax.
Now the dark side. If you use it and your wood can't dry fast enough, it gives black mildew a good foothold. Be cautious on light-colored woods, spinning as much unbound water as you can out on the lathe, allow to dry under a roof until the surface is even in color - no dark wet surfaces on the endgrain - and then apply before racking if you feel you need it.
For logs, wouldn't waste the time. Staple a piece of cardboard over the end to slow loss and discard the end checks as you harvest blanks, or heap the chainsaw shavings over the end. Highest percentage of usable wood goes to roughed blanks, so the sooner you reduce your log to them, the better. Second to whole log harvested as needed. Lowest to "turning blanks," which have as a couple have mentioned, a greater or lesser tendency to develop radial checks, depending on the species.