Using a dishwasher is pretty safe because the water is deionised and doesn't contain much in the way of impurities. What if your keyboard is too big to fit..?
Well, I've got a small dish washer and a big keyboard which I love - an original IBM AT model. It has a lovely clunky feeling that you just don't get with modern keyboards, and my typing speed with it is about twice what it is with the flimsy piece of shit that came with this PC. But I'm also balding and have a beard, which means I shed a lot of hair, and tend to eat while I'm working occasionally. The result after several years of never actually getting round to cleaning it was that my keyboard was FILTHY - you could barely see the plastic, and it was full of hair.
So yesterday I plugged in the flimsy piece of shit and took my fine vintage keyboard to the bathroom, where I leaned it on its end and gave it a hot shower and scrub with a scrubbing brush and washing up liquid. Got rid of tons of hair and other less identifiable crap, gave it a good shake, three or four times, to get rid of the water, and left it to dry in the warmest part of the flat. And of course...
...I just plugged it back in and it works perfectly! Bwah hah hah hah hah!
The moral is that sometimes things work the way they're supposed to. Not very exciting I know, but reasonably good news, and possibly helpful to someone else with a mucky keyboard.