I accidentally sent the iPhone through the laundry, full wash and most of the dry cycle—when I heard thumping in the dryer. I first ordered and attempted to replace the battery, and then I saw the motherboard contacts were corroded and some broken. So I ordered a motherboard from the cheapest carrier, since this is a spare device I mainly use for remote control apps and music.
It went well, a little slower than expected. But all functionality worked well after re-assembly.
The small items around the camera are a bit tricky, and the copper contact piece that touches the back cover once re-assembled is hard to visualize from the guides. Definitely look at this piece before removing it.
When replacing the logic board, getting the 5 ribbons to all align correctly while putting the board in place is a bit tricky as well. Take your time. I waited a few weeks after receiving all the parts until I knew I had a block of time when I could do this uninterrupted.