Just a quick update. I decided to not try the axle grease as a first attempt, and had a can of LiquidWrench "Dry Lubricant" in the house. It's sort of a cross between silicone spray and white lithium grease - except it dries without any residue and leaves a coating of what looks like a dry, white lithium behind. Sprayed all 4 corners liberally and ran 4 loads this weekend and it's still quiet as a mouse. Not sure exactly how long it'll last, but so far so good.
I looked a little more closely at the lube that LG uses from the factory, and it's really odd. It's a clear lube, but VERY sticky - almost to the point where it can get wiggled out of the way and then make a bit of a sticky snapping noise when the mounting discs move from side to side (imaging the sound your shoe makes on a hard floor with something sticky on it as you walk along). Anyway, not sure what purpose it serves except it appears to not flow back into its original position if it gets moved away with continued use in a particular area...
Anyway, so far so good. Once you know how to open the hood (I used a plastic putty tool) it's easy to get to. Not a hassle to address in the future.