Ballpoint pens do dry out if you don't use them for a couple of years. You will notice that ballpoint pens stop gliding nicely before they dry out completely. They can still be used
to write something but the ink does not flow easily and you have to press the pen
a bit onto the paper to get it to write. It is in this stage of the drying out process that you can revive the ballpoint refills easily. They will be like new. Note that this method can not fix ballpoint pens which are actually empty or ballpoint pens that have
been droped on a hard surface such that the tiny ball on the tip has been damaged (has a dent). However most ball pens simply dry out and you don't have to throw them away. You can fix them.
You need a jar with a metal lid and that jar needs to be high enough for the ballpoint
refill to stand upright in the jar.