It is definitely a bad thing. Someone on the forum once asked about cleaning them with vinegar. That makes lead acetate, a sweet tasting compound that is highly toxic. It is also called sugar of lead and was the drying agent in paint until it was banned.Is that white corrosion on the lead a bad thing?
That is 'white lead' Lead oxide, extremely poisonous, don't get it in your mouth, and don't handle it with your bare hands. The oil or WD40 keeps the lead from 'rusting' and developing a dusty white powder which is the oxide.Is that white corrosion on the lead a bad thing?