Some lenses have a fair amount of grease, some don't. An old trick is to use grease to "hide" wide tolerance.
It is this grease that dries up over the years, and makes both the zoom and focus stiff on many older lenses.
Putting any kind of liquid into a lens in an uncontrollable fashion is very risky. I don't know of any way to "rejuvinate" compressed/worn felt or velvet except to replace it. This is what I have to do with the negative carrier on my Durst L1000, where the velvet material has compressed flat.