I just did my girlfriends engine yesterday (2002 ford escort), I didn't cover anything and rinsed the degreaser with a light mist - medium spray, afterwards I just soaked up any pools of water I saw and let the car sit and dry. I didn't have any problems.
(used the routine from another thread on the engine, zep citrus degreaser 1:1, rinse, dry and armor all tire foam) It turned out pretty good.
Before

After

(used the routine from another thread on the engine, zep citrus degreaser 1:1, rinse, dry and armor all tire foam) It turned out pretty good.
Before

After
