First remove your iPhone from the case, then use a soft, slightly damp, lint-free cloth to wipe both the outside and inside of the case. Avoid using window cleaners, household cleaners, or abrasive substances, and make sure the case is fully dry before putting it back on your iPhone

Yes, but only if the alcohol type is correct, use 70% isopropyl alcohol or 75% ethyl alcohol wipes. Avoid anything stronger, and don’t use bleach or hydrogen peroxide-based products

Generally, it’s not recommended. Dishwashers can expose your case to high temperatures and harsh detergents so handwashing with mild soap and water is a safer option. If you accidentally put your case in the dishwasher, remove it promptly and let it air dry.