You don't want to put oil or grease on the one way bearing it nesses them up I have replaced a bunch of them for customers who have oiled them.
Not entirely true. I use a very light coat of oil and have never had a problem. Ive actually heard opposite and that it is bad to grease them. But generally I think either works just don't over due either one. That's where you can have problems.
Forgot to add that most will come from the factory with grease but this doesnt necessarily mean grease is the best option. Most manufacturers will grease a majority of the components in the reel because they don't know how long it will set on the shelf and they also dont know if the customer buying the reel will ever have it serviced and since grease lasts longer they use grease.