That's not leakage. Its oil that seeped down off the threads of the cap from when you removed it. If you wipe the top of the bottle, then the inside of the cap before reinstalling it, you wont get this happening. I had oil all over my shelves before I started doing this, cursing the stupid oil companies for using cheap, leaky bottles that for some reason only leaked after I had opened them. Then I did an experiment and started wiping the bottle threads and inside the cap... suddenly the problem stopped happening.
As far as milk jugs, I have a few in my workshop I've been too lazy to take to Autozone, I know a couple of them have been there over a year shoved up against the wall in the back corner. Havent had a problem with those leaking, however if they are very full and the cap is on tight, if you accidently kick them or bump them with anything, they will crack open in a big dang hurry.