I would never use oil of any kind on parts that live in a climate of dust and grit. Oil gets sticky and collects dirt.
I use a dry silicone spray (as recommended by the manufacturer) on my Roadmaster stainless steel towbar. When (not if) it sticks, I just use it exactly the way I used my old fixed arm towbar. Once it is disconnected, it releases and folds just the way it is designed to do.
No hammer, no problem.
CM1, USN (RET)
2017 Jayco TT
Daily Driver: '14 Subaru Outback
1998 Dodge QC LWB, Cummins, 5 speed, 4X2
2 Kawasaki Brute Force 750 ATVs.
Pride Raptor 3 wheeled off-road capable mobility scooter
"When seconds count, help is only minutes away!"