When an iron skillet has been washed in water, the tool is not damaged but can be salvaged. You can season the skillet by first pre-heating oven to 325 degree Celsius. Apply skillet with warm, soapy water to soften the gunk. Using steel wool, scouring powder and even sandpaper, scrub to remove the gunk. Dry it thoroughly and apply a thin coat of cooking oil. Get additional details from http://www.thekitchn.com/technique-seaso-6719 .
All we use it Cast Iron pans. Once you have cleaned and seasoned it the first time NEVER use soap on it again! Wash only with hot water and a scrub brush. When all your food is removed from the surface place on stove top and heat. Add a small amount of cooking oil and wipe around the inside with several dry paper towels in a wad. Be VERY careful not to burn yourself while doing it.