My tools serve me, not the other way around. It's not worth the time and effort to wash by hand or sharpen on a whetstone. I don't need an expensive knife to cook at home. A pull through sharpener and honing steel are adequate. Get the right material and you don't have to worry about the metal in the dishwasher.
The detergent in the dishwasher is extremely corrosive. Most kinds of metal can't stand it, and you see the general result (rust) after just one try. So, if your knives are OK with it once, they are OK with it all times.
But: they are going to loose sharpness much quicker. You will have to sharpen them more often. I guess you are OK with that, too.