My friend had a citronella candle on his patio and the thing ended up getting so hot that it kind of burnt through the metal and all of the wax stained the cement. He got all of the excess wax removed, but there is still the stain that has penetrated the bricks. I guess he tried using a power washer and tried using Goof Off, but those did nothing. Any ideas for what can penetrate and get rid of the stain marks? Thanks
-d