Here's what I would do:
Clean the ball and socket thoroughly, then use a DRY film type lube. Personally, I'd use Molybdenum Disulphide in a spray form with alcohol as the carrier.
The ancohol dries off and leaves a very thin, dry coat that does not attract dust and gunk. If you're not familiar with
Moly, it is one of the slickest substances known to man. Teflon feels like fine sand-paper, and silicon like sludge in comparison. Obviously, considering it's so slick, it should be used VERY sparingly, and discertely!
It is also inflamable and a highly toxic substance, BTW.
I use the dry Moly spray by Birchwood Casey for firearms from Chye Whatt Seng (gun shop) at Golden Mile Complex. The last time I bought it about 5 years ago for about $12/can. I still have it and use it fo all sorts of stuff that requires a very high level of lubrication!!!