I bought that little bottle of oil on eBay, as someone mentioned on here. I have ONLY used it on one thing: my shooter rod. It makes a world of difference! Just the tiniest couple of drops will make a rough shooter rod 'oh so smooth'. I've even had some that would make a very slight gritty sounding noise, and after putting a drop or two on it, it stopped making the noise and shot a ball like a new assembly would.
As far as I can tell, I can't see any problem with this. The oil can't go anywere else that I see, and it stays on the metal.