I use synthetic motor oil (mobil 1 10w-30) on my leadscrews. Makes them smooth and it doesent seem to attract the chips as badly as a greasy product for me. I also thought about adding brass gibs on the mill. The 7x lathe I have has been converted to brass gibs and seems good. I also have been thinking about oil impregnated bronze for the gibs. Its a little tougher than brass and it is made for bushings anyways. Just my 2 pennys though.