As an auto mechanic, I often use clean motor oil to lube my pivots, it works well. To those that act like motor oil is the devil, I say they need to quit being so hyper critical and sensitive. I’m exposed to it daily in quantities far greater than most will contact in a lifetime and it’s not what’s gonna do me in, women, taxes, and age will.
I actually prefer grease for the more hydraulic feel of the action, but some pivots like slip joints only see oil.
At home I use whatever is handy as well, mineral oil, Lucas gun oil, hoppes gun oil, but my favorite is probably the kleen bore gun oil, it’s quite a bit more viscous than the others and smells of nostalgia.
It’s a knife, don’t overthink it.
There aren’t great shearing forces, dramatic temperatures, or hundreds of thousands of cycles like other machines face. Any petrol based lubricant will do a fine job.