Yes thats worth doing, if a duckling has a challenging or very long hatch, it's always worth giving them a boost once they're out.
I'd wait for her to dry, which should only take an hour or so, then see if she'll take a sip. If you have any nutri drench, you could add a little to her water...
Can you see any veins, how much blood was lost? Just a little? Or a lot?
Is he yawning or chewing?
Day 5 since internal pip or external? They can go two days without food or water once the yolk is completely absorbed. And the yolk isn't usually absorbed fully until after external pip.
Do you...