We all know (or should know ) that you need to put a couple of drops of thin CA in the screw holes to harden the threads.

The problem is HOW DO YOU DO IT WITHOUT MAKING A MESS ?

The answer

Get a piece of scrap music wire about 1/16" in diameter. Stick the end of the wire in the screw hole at an angle.
You just want the wire to barely go in the hole. Now put the ca on the wire. It will run down the wire into the
hole and not make a mess of everything.