Goal and options: What can I do when My sharpie Pen dries out?
output answer: Soak the tip of the marker/pen in rubbing alcohol for about 10 min., it will soften and renew it.

Goal and options: To make a water resistant handle for a knife, you can
output answer: Use metal

Goal and options: how to cut through scum in the bath tub.
output answer:
use castile soap and hot water.