My daughter and I put artificial snow on the outside brick of our house and now there seems to be a semi permanent white like stain on all of the places that we put the snow on the brick. We've tried many times to remove this stain but it comes back every time, so we've turned to you. What can we use to remove this awful looking stain before winter turns into spring and the snow that should have melted never did. Is there a stain that can help us? We appreciate any advice. Thank you.