Electrical Contact Cleaner or motor cleaner is the safest to use in my opinion.
I had to have a bumper painted because I was a nice guy and cleaned the locks on a car with brake cleaner. It ran down through a weep hole in the trunk lock and left a nice bleached out stripe on a black plastic bumper of a Mitsu Eclipse.
Carb cleaner will soften paint and remove clear finishes that is used on brass hardware. It can also bleach/stain a beautifully stained wooden door. Just ask me how I know.
Have never had issues with contact cleaner except for the smell.