[MadMax]

Silicone oil has the strange property of not staying in place. It will spread continuously until it has become a molecularly thin layer. This is a good property for penetrating cracks and spreading evenly (good for rust protection), but it's kind of crap for providing higher pressure lubrication. Perhaps it's most useful property in airsoft is that it's inert and doesn't attack many plastics or rubbers. It's good for conditioning rubbers and preventing them from cracking which is why I recommend it as a seal conditioner only.

I find that a very light application of teflon or white lithium grease works much better for slide rails. I dab on a bit onto slide rails. Install the slide and cycle it a bunch of times to spread the goo then wipe it off with a paper towel to leave a very thin film. Gobs of grease can pick up sand and dust which makes for an abrasive emulsion I call "gun smegma". I am also experimenting with graphite powder which I lightly dust onto the rails before the cycle and wipe. The graphite makes for very dry film. You can wipe nearly all of it off after cycling the slide. The only downside is that you have to thorougly wipe it out of the external surfaces because it can transfer to holsters, gear, and eventually smudge things like a sofa or your face. You can find graphite powder at Crappy Tire in the automotive section. It's used as a door lock lubricant.