A few months ago I spilled about 300ml of water on top of my MacBook Pro. It's one of the newer models with the touchbar and the terrible butterfly keyboard (otherwise it's a fantastic machine though). The spillage happened just as I was about to finish work for the day. There was a lot of water there on top of the keyboard. It took me 5 or 6 large napkins to dry it out, even after having drained it first by leaning it sideways. I closed the laptop, put it on its case and went home for the day.
Next morning I took it off the case at work and switched it on, just to find the display behaving oddly (weird colours and artefacts). After a few minutes, the display froze and I believe the whole computer did too. I force-rebooted it and the same thing happened, only this time a lot quicker. After a third time I decided to keep it shut down and head back home to get my backup computer.
I made an appointment at the Apple store and took it in. I described what happened precisely, didn't leave a single detail out. They took it in, found zero water damage but acknowledged the problems. I was told it could take up to 10 days as I use a US keyboard (this happened in London) and they might not have one in stock.
About 4 days later I got a call to pick it up. They had replaced the logic board and the display and cleaned up the keyboard, all free of charge. I do have Apple Care on it but if I recall correctly this was done under warranty and would have happened regardless.