Don Young wrote:

I wonder why some of my screwdrivers have steel shanks all the way through
and large steel caps on the back end? Actually, I have been an apprentice
and a journeyman electrician, tightened many locknuts, and used either
"ChannelLocks" or a screwdriver with either a hammer or a pair of "Kleins"
to hit it with, depending on access to the locknut and what tool was in my
hands at the time. Either way works good.

I second the Kleins-and-screwdriver method.

I've also found that if I had-tighten the locknut it will provide enough
tension that the external fitting can be rotated tight with Kleins without
having to hammer on the lock nut.

I'm not an apprentice or a journeyman, but I know what a pair of Kleins are.