Please tell me you are kidding ?
How did you plan to handle all the corrosion that will happen internally from having the wire soaking in water now too perhaps ?
(Not like just hosing off the engine bay, where the water is going to run off the loom)
I would have just used some liquid/spray degreaser and wiped down the loom with a rag. Orange hand cleaner and a rag works good for cleaning wiring too. Just take your time and do each wire at a time pretty much.
Don't even want to think about what chemicals and residue might be left in the dish washer now if you ever washed dishes in it again too.