Most of todays reels have drain holes or openings in the frames. If your blasting a reel with a hose, your forcing water into it. This will break down the grease, lubricants and also rust any parts that may not be intended for a good soaking.
Engaging the drag, ( do not have to crank down all the way, just enough to engage it) will keep water out. If you look at many conventional reels, you will notice that the spool moves as you engage the lever drag handle. You should absolutely engage it to clean and loosen back up to store it, to avoid flat spots in the drag washers.
Whatever you use, make sure it will not eat away at your line ( braid & mono) ... most times a simple dish soap is plenty strong enough.
NEVER leave the drag loose when spraying your reels or at the side of the boat when running out! Saltwater spraying into the reel is the worst thing you can do!
