Spray the porcelain tile with a non-abrasive cleaner. Let the spray soak into the stain for two minutes.
Wrap a thick, damp cloth around the bristles of the wire brush. Examine the cloth-wrapped head of the brush to make sure the tips of the bristles are not sticking through the cloth.
Scrub the area gently with the cloth-wrapped wire brush. Rub the head of the brush over the stain in small circular motions until the stain is gone.
Wipe the area with a clean, dry rag. Check your work. Repeat if necessary to remove any remaining stains.
Spray the porcelain with tile and grout sealer. Let the sealer cure overnight before using the surface.