If you have a Furlex you can download the instructions from the Selden site. There are 4 points lubricate. 3 are easy and the fourth a bit more tricky, but needs doing less often. I have just done mine with Lewmar grease, administered with a syringe so goes straight into the holes with no mess.
My reefing furler is a Colnbrook Seareef and lubrication is made to a hole in the lower section of the foil, about 3-4 inches above the spool, a 3 in 1 oil is recommended for this one; I only discovered mine by accident reading in some of the manuals I had, and what a difference it makes!!
Grease or oil I guess is the proper lubricant where needed - not WD40 or similar.
The upper swivels on some rigs are 'sealed' bearings and cannot be lubricated this way.
Facnor does benefit from a good flush with fresh water, and make sure to flush the top swivel as well. Two to three times a year the top swivel is dropped to clean it, makes a noticable difference