I don't and have never had a problem on my Lazer so when I built my B44 I didn't use any either.
I think the reason is that as the plastic beds in (allegedly
) the tiny bits of plastic makes a grinding paste with th egrease and wears the gears quicker. If you don't use grease then the bit that wears off becomes dust that sticks to the gearbox casing. Something like that anyway, I am no expert
