I've often thought about returning Bic biros to Bic when I've used up all the ink, and asking if I qualify for some sort of award!!
Licking the point sometimes gets them started again.
Stir your hot coffee with them Or you could use a cup of hot water! Gives them a new lease of life. You could also try shaking hard, as if you were going to throw it away but don't let go.
Good luck.