You should only have to push it into the morse taper with your hands.

Once it is in it should be difficult to remove and the drive or the
chuck should not spin inside. If it does you may have a slight defect
either on the drill chuck or drive or inside the taper.

All it takes is a little grit getting inside the taper and metal can
build up and keep your drive from seating correctly.

I had a problem inside my taper. I ended up buying a reamer from msc.
After a few turns of the reamer the problem was solved.

C & S wrote:
Perhaps a silly question, but is there more to properly setting a drill
chuck or drive center with a morse taper, than to completely degrease it an
give it a good whack with a wooden mallet?

Thanks,

Steve