Cast iron griddles are great for cooking steaks, chops, burgers and other meats because they conduct heat well and are non-stick when properly seasoned. Cleaning a cast iron griddle requires a different technique from cleaning a griddle that isn't made from cast iron. Incorrect cleaning risks ruining your cast iron griddle, while proper cleaning will help it last for years.
Let the cast iron griddle cool to room temperature before cleaning it to prevent burns and possible damage to your griddle.
Rinse the cast iron griddle with clean water. Soap can ruin a seasoned griddle, so don't use it. Wipe it with a clean sponge or rag.
If there's food stuck on the griddle, combine 2 tbsp each of water and cooking salt to make a thick paste. Scrub the stuck food off the griddle using the paste, and then rinse with water.
Dry the griddle and rub the cooking surface all over with a little cooking oil on a towel. Any cooking oil will do, but you may want to use peanut oil if you use your griddle over an open fire or otherwise cook with it at very high temperatures. Peanut oil will cause less smoke at high heat than other oils. There should be just a light coating of oil on your griddle. Wipe with a dry towel to remove any excess oil.
Put the griddle in the oven at 120C for an hour to additionally season it before storage. Let it cool in the oven, wipe it down with a towel one more time and store it.
Pre-seasoned cast iron griddles are readily available if you don't know how to season one.
Remove rust from a cast iron griddle with steel wool.
Never use soap on any cast iron cookware. It will ruin the seasoning.