I've never had to treat the saddle or nut with anything in yeeeaaars of playing over many acoustics (and my style is rock and contemp so there's lots of string bending and agressive strumming/picking). Electrics, yes, and that's likely because of the playing style and such, and even then, only a bit of pencil lead in the nut at string changes ...that's it. But for acoustics, never. It shouldn't need it. If you are having tuning issues check your string-winding procedure, then your nut-slots (may be rough or tight, especially if you went up a gauge). A proper nut/saddle on an acoustic doesn't need any treatment, IMHO.
Edward