Cleaning a piece of cured and stamped concrete in a dishwasher is not recommended and can lead to various issues. Concrete is a porous material, and using a dishwasher to clean it could cause damage to both the dishwasher and the concrete piece itself.
Dishwasher toxicity: The curing process of concrete involves the use of various chemicals and additives, such as cement, water, and possibly other substances for coloring and hardening. If you were to clean cured concrete in a dishwasher, some of these chemicals might leach out into the dishwasher water. As a result, there could be a risk of contaminating other dishes with potentially harmful substances, depending on the types and amounts of chemicals used in the concrete.
Concrete "sand": Concrete is composed of various aggregates, including sand, which gives it its texture and appearance. When cleaned in a dishwasher, small particles of concrete, also known as "concrete sand," could break off and end up in the dishwasher's filters, spray arms, and drainage system. This could clog the dishwasher and may require thorough cleaning to remove the concrete particles.
To avoid any potential hazards and damage, it's best to clean concrete items using more appropriate methods. Handwashing with mild soap and water would be a safer approach for cleaning cured and stamped concrete items. Additionally, avoid using harsh chemicals or abrasive scrubbers, as these can also damage the surface of the concrete.