I've found my dishwasher to be a very through way to clean out a gunky knife.
Some dishwasher soaps are very harsh. They can damage, pit, and stain some common knife materials and leave others distressed. G10 will come out with a gray cast. It can be restored by treating it with a spray of WD40.
Water and heat together can accelerate rust on rust-prone alloys.
Many dishwashers can get very hot too which can be problematic for knives. I recommend top-rack only so that the knives aren't so close to the heating element. Some washers have an "energy saver" setting which disables the heating element dry cycle which would be a wise move for washing knives.
Other than that, must be sure that you dry the knives out throughly and then reoil them immediately.
I know someone's wife that put his stag handled Cold Steel Trailmaster Bowie in the dishwasher.Not only did the blade rust but the stag came out chaulky white.
One of his friends from Camillus Cultery
had the blade reground and the handle polished.It almost looks good as new.
The elevated temperature and harsh detergent in a dish washer are very hard on anything but 100% stainless steel. The washer and detergent system are optimised for ceramics, aluminum, stainless steel and glass. There are chemicals in the detergent to try and reduce etching of these materials; anything else is subject to being etched.
The only knives I wash in the dishwasher, are our butter knives. I clean my knives like a fine firearm, although water is needed ocasionally. Then I clean them in the sink by hand, like our fine steak knives. RKBA!