This is another one of those myth's that was right at one time, like not putting a battery on a concrete floor, or it will get discharged.
I think it was probably 30-40 years ago, some gear lubes had a lot of sulphur in them, and I guess with water contamination and age, you could get sulphuric acid to form in the mixture, and that attacked bronze / brass materials.
Use a name brand high quality oil, and you won't have any problems.
If you were wondering about the battery myth, it was true when battery cases were made of wood, when was the last time you saw a wood cased battery at the local auto parts store ?
So that shows you how long that myth has been around !!!
