That's precisely why I've never even used a dishwasher, despite the many reports that say it works. I've always been afraid of water getting into places that it could not so easily escape from, even after a day of sunlight outdoors. There's just something about "water and electronics" that don't mix!
So what I've done is use Dehydrated Ethanol (99.8% pure). It takes more work than a dishwasher would, but I rest easier at night! Ethanol leaves no residue whatsoever and evaporates very quickly. Works great to clean up old SE/30 motherboards with spilled electrolytic capacitor fluid.