NO grease,just gathers grit and gunk and then acts as a lapping compound. I use mil-tac,or mobil -1 5w30,sometimes, any good oils fine,light use. For years I have told most non gun savvy people to justr buy a can of 3 in 1 oil at the grocery store. Sometimes they look at me crazy ,like it doesnt say GUN oil.
This month in American HG mag ,Bowen talks about lube and says 3 in 1 is good oil,I think I will cut it out HA! Good Luck