Diff plates corrode pretty quickly when they have been wet. I can tell you that from personal experience desite me drying my car with a hair dryer after giving it a "bed bath" with a wet toothbrush
My personal opinion is that i wouldnt unless i had removed all the bearings and diffs first. Water will sit in the bearings and corrode them making them a little notchy unless you remove them individually, blow the water out and re oil them.
I take my car to bits to clean it now.
Thats my 2p and experience anyway.