My brother's comment about his frozen lock made me stop using WD-40 as a de-icer.
He called me last week after his car door handle snapped off, saying 'I sprayed it like you told me and the plastic just cracked in the cold.' I'd been using that trick for years, but it turns out the propellant can make some plastics brittle below freezing. What do you use on a frozen lock that's actually safe?
Funny enough, I used to swear by WD-40 for that too. Hearing about your brother's handle makes a lot of sense now. The rubbing alcohol trick is a much safer bet.
Actually, WD-40 can leave a residue that attracts more dust. The alcohol evaporates completely and cleans better. That's why it's the move for electronics.