It's OK 2wash out the intake manifold, but first(
I'd remove the nuts that hold the fuel rail in place and take it and the injectors off. The injectors will stay attached to the fuel rail if you leave the top clips in place. The bottom of the injectors are just stuck into the manifold with a o-ring to seal them. Pretty easy to remove the whole works, just pull up after you remove the nuts.
Dawn dishwashing liquid and hot water does a great job of cleaning oil and grease.
I saw your post above about the oil separater, you don't want to go there unless you were having problems that a ned CCV didn't fix. You will need to pull off the front timing chain cover to get at it.
Valley pan and t coolant pipes look OK?
You may want to just give the bolts that hold the VP down a slight turn to make sure all of them are tight enough, don't over do it.