I pressure wash before I start removing the engine. I throw all my nuts and bolts into a bucket with white vinegar for a couple of days. Wash them in water and baking soda and a steel brush to remove grease. Wash them in parts washing fluid and brush again if needed.
Pressure was the engine block, heads, pan, etc. and then bring it all down to a shop for baking and washing.
Most of my cleanup isn't needed, but I like to bring my stuff in cleaned up.
