I'm really not clued up on oils, but thinner oil seem to last longer in locks before it goes skanky and gums the lock up, although thick oil and grease slows the pins when they drop down; this is documented as making locks easier to pick in some instances although obviously, it's probably more trouble than it's worth for recreational picking.
There are plenty of cheap locks that I find a pain to pick, but I also find they open quite easily when raked with a bit of 'bounce' on the tension wrench. Really heavy tension on the plug often sorts these cheapy locks out too, although it's harsh on the lock mechanism and you will likely have to manually set any security pins that catch... Obviously this is OTT for general home picking but it has its uses.
I'd leave the piece of junk alone and work on a better lock, it's probably going to be more enjoyable/productive.
