Clean a wrought iron doormat with warm, soapy water and a soft brush. For detailed areas, use a toothbrush or a similarly small brush to get inside all the curved areas.
Dishwashing soap is ideal for removing grime from the doormat, but mild household cleaners are also appropriate if they are labeled as safe for use on iron. You can also use a half-cup of white vinegar in 2 liters of water.
Make sure to rinse the entire doormat thoroughly and allow it to dry before setting it back down on the porch. Towel-drying the iron helps, especially if it is humid outside and the water isn’t evaporating quickly.