When I was just young lad I worked part-time at one of those mom and pop computer fixit shops. Every once in a while the owner would buy a palette of Model M keyboards. I'd get stuck with the job of refurbishing them for sale or inclusion with new systems. I'd spend a couple weeks taking off all the keys, scrubbing the keyboards down with a dishwashing tools and soap and then toss 6 or 7 into the kitchen dishwasher for a cycle. After a week of drying they were good to go for $10-15.
We never had a keyboard that didn't work after this "refurbishment". Absolutely built like tanks.
So it's weird to see keyboards like the Model M going for $100+. And I agree that they're nice typers. But then again I'm using the same $10 Logitech I bought at Ross (of all places) when I realized I needed a USB keyboard for something 10 years ago. I toss it in the dish washer a couple times a year to clean the cruft out, but other then some faded keys it works "fine".
The only expensive keyboard I've bought was one of those Bluetooth Mac chiclet keyboards and only because I was using my rMBP as a second monitor and needed something a bit closer to type on. It's okay, but I wish sometimes I had bought the $15 bluetooth keyboards I see at Ross every so often.
Yeah, but I wouldn't do it with anything too expensive/has batteries etc., and you gotta give it a couple days to dry out so nothing shorts inside of it. The rinse cycle is usually fine. You may or may not want to use soap, I usually wash it with dish soap and a brush first then rinse it in the washer.