Like someone else mentioned use an electrical contact cleaner.
We carry a can in a bay and use it quite a bit on grody connections at campgrounds.
Sometimes someone has unplugged without tripping the breakers. I always check to see, that they are off. 90% of the time our generator is running,in ssummer, when we back into the site.
I make sure the breakers are off, plug in cut on breakers and after 90 seconds or so the surge protector lets power, to the coach and circuits automatically switch.
Sometimes we see a hot pedestal,m as in heat. I will try cleaning the receptacle again. That don't work call the Host. If I had the time and wnated to I would pull it apart but not hot. I don't think they would want me working on it.
We've had one 50 amp cord melt at the end, with our Fifth Wheel.
Our most frequent destination, in Michigan, I've noticed they have Inspectors come around checking the electrical pedestals etc. They are not Campground's Folks. Must be County or Electrical Supplier.
I imagine one of the Prevost etc with five airs running might cause a definate breaker problem and pop some around the campground, especially with two cords and 100 amp service, plugging into a pedestal, that the breaker is on, and everything in the coach running.