What happens if you don't remove the rust ring? I've been dinged with four steel splinters in my eyes. I went to a clinic to get three of them removed and I got the last one out myself, but I don't think the rust ring was removed after any of them.
Agree- practice on a hard boiled egg rolled in dirt or iron shavings.
as far as the rust ring- if it's not too deep I use the burr to remove it. for deeper rust I refer them to ophtho. for FBs not terribly deep I use the eye spud as my first line tool and use the burr for deeper ones.