I don't like the idea of blowing the nasty hard gunk into
the bearings so I usually remove, clean or replaece and reinstall the zerks
that won't take grease.

Glenn


I used to have an English car, that instead of nipples had plugs on all
grease points. The advice was to remove plug, fit a clean nipple and
then grease. Quite a job!
For suspension parts, lifting vehicle off ground (not by the wheels)
helps get the grease where it's needed.