Really pleased you have solved your problem, I am going to keep on top of my hitch cleaning from now on. When I first had the creaking my mind slipped into overdrive re-how much it would cost etc. But following the advice on the forum, a few minutes and a tin of brake spray problem solved. Also the point about exhaust contamination would have never entered my head but for the comments received.
All the best regards Brian
All the best regards Brian