I have not used olive for that purpose.
I try to use products that perform well but also don't present any potential harm.This is the primary reason that I stumbled upon the use of olive oil.
I studied nutrition in school and one vital lesson I learned,beyond the text books and my professors lectures,was that nutrition was the key to achieving optimum health.It also is a key factor in avoiding the most common maladies that plague Western man.Along with my formal education in nutrition I learned to become keenly aware of products that may pose potential harm and to avoid them.
This is a long winded way of explaining how I stumbled upon the use of olive oil.When I was looking for a substance to ameliorate the cracks in the wood handle of a new Puma #725 4-Star folding knife, I was stymied by the failure of numerous commercial substances.I happened to broach this topic with one of my former professors and he suggested that I try a natural oil like walnut or olive oil.He said he had used these oils for his kitchen cutting boards and they worked exceptionally well.
To make along story short I didn't have any walnut oil,so I used what we had in the kitchen,olive oil.It worked so well in closing the cracks in the handle of this Puma that I've used it ever since.This was in 1988.
To answer your question about the pivot pin,I use an oil provided with new Benelli shotguns.I have quite a large supply of this because one of my relatives is in the firearms business,it's free and has proven effective.I use a small amount and it doesn't come into contact with my hands.I believe there are many commercial products that will work well for this application,so you should have large list from which to choose.
Good luck and buy those Buck knives.LOL