How do I get a 92 Chevy Caprice hood unstuck?

I pop the latch and nothing happens. I have to pound on it (can go on for 20 minutes) to make it come unstuck. I'm going to get some type of rust prevention stuff because the hood latch is rusting. What kind of lubricant should I get to compliment this? No WD40 either, already tried that. It works all of 2 days, then it's back to being stuck. I need a grease type lubricant. What lube and what rust preventer do I get?