1. Crystal
This is more like common sense because all the expensive crystal glasses should be washed by hand, even if you have a high-quality dishwasher that has a delicate washing program. Items move around a little bit in the dishwasher during the wash cycle, and when that happens in combination with abrasive detergents, the glass eventually becomes hazy and pitted, and you won’t be able to fix it afterwards. They will come out of the dishwasher pretty damaged, and they won’t be as clean as they should be if you wash them by hand.
2. Pressure cooker lids
Despite the fact that some pressure cookers have dishwasher-safe lids, the general recommendation is to keep them away from your dishwasher. If you want to have your pressure cooker for a longer period of time, the best way to wash it is by hand. During the dishwasher’s cycle, a lot of tiny pieces of food circulate through the machine, and if by accident one of these gets stuck in the valves or vents without even realizing it, it might seriously damage the pressure cooker.
