Ummm... why not just buy a new keyboard. They are cheap.
Disconnect the keyboard, get rubbing alcohol and a couple of coffee filters and clean away. Even if you spill a ton of the rubbign alcohol, it evaporates fast enough that it does not damage and it is very effective at cleaning stuff off keyboards, monitors, computer cases, etc. A paper towel or cloth will work too, but the coffee filter is lintless.
If the keys pop off, you can use something to blow the crumbs out underneath and even clean with the alcohol there. I've been a fully qualified computer nerd for more than 15 years and I quit buying any fancy stuff to clean computer equipment with years ago.