Cam, if the oil is not off, you cannot keep ink on the nib. - It won't "gather" on the underside of the nib, above the tines & below the breather hole. Instead, it will slide right off the nib. It doesn't take much to get the oil off. - You can spit on it, if you don't mind that. Or, dip the nip in rubbing alcohol & then rinse in running water. You should be then good to go! If you prep your nib BEFORE you insert it in the nib holder, then you may get more oil (from your fingers) on the nib, which will once again cause it to resist ink. I use some small jewelry-making pliers to insert my nibs, so I keep my hands completely off of them after they are prepared.
Post back if you still have any questions!
Janis