How often should I apply lubrication?

[roar]

I know that AR-15s love to be run wet, but I also hear about how if the rifle is decently clean, it will still run. How often should I re-lube a completely cleaned AR-15 that is kept for home defense?

For what it's worth, I clean and lube my Glocks once a month, but I know that I could let them go much longer, and even run them dry for the most part, and they would still run.

How little is too little for a cleaned AR?

[Constructor]

Drop some Mobil 1 on it once a year if not being shot.
Mobil 1 will stay on the parts longer than most gun lubes but it is not so sticky that it collects dust and grit. Most ARs will shoot a few hundred rounds easily completely dry.