I have been in this habit for years now and have had ZERO issues. Lightly hose down the engine compartment and motor with water, use a rag to wipe off any built up debris, than I lightly hose it off again. With EVERYTHING still wet, I liberally spray Armor All on the motor, air cleaner, fuse box, brake booster, radiator, battery, everything. Shut the hood. Then wash the rest of the truck. When done, open up the hood and tell me if it doesn't look brand new. Next time you do it, that Armor All is still on there and makes it easier to wipe right up. Just my method though.
I mist, wipe, mist, spray, and walk away