My guess for not using a chastity belt in a dishwasher is because a dishwasher doesn't have the same cleaning pressure as humans when we scrub and scrap the thin edges that a water jet wouldn't reach or clean thoroughly. Last time I used a dishwasher, it was a few months ago, because I was feeling lazy and wanted to get it done while I was doing laundry and other stuff. The dam thing ended up taking over 2 hours to clean my dishes and a few tough stains couldn't wash off, so I had to scrub everything myself with the rough side of the sponge, and I was done cleaning all my dishes in 20 minutes. During those 2 hours, I was able to clean the bathroom, do my laundry, and sweep the floor a bit, as well as take my dogs out.
So, forget the dishwasher.