We covered everything under the hood with boxes of baking soda, it looked like it had sat out in a snowstorm.  When we pressure washed the whole engine bay and one more light coating of baking soda to see if we missed anything the first go around and washed it a second time.  I am sure we will see some rust later down the road, but cleaned it the best we could.  The jeans and tee shirt I had on have pin holes all over then from the battery acid just pressure washing it after the fact.