Q: When I shake the top, I hear water. How do I get it out to prevent mildew?

First, make sure you "pump" the sprayer to get rid of any excess water.

There isn't a way to take apart the top of the cloth wipe sprayer into pieces, but if there's water "locked" in at the top that's not being squirted out, you can open the top by pressing down on the trigger with one hand, then lifting up the top from where the black nozzle is and shake water out. 

Alternatively, vinegar is naturally antimicrobial. Simply pour vinegar (white or any other kind) into a bowl and place the nozzle inside. Let it sit for a few minutes to kill and dissolve any possible fungus, then you can let air-dry. Hydrogen peroxide is another way to kill mildew naturally.