I just bought a large wool rug - it's white-ish. BEFORE I put it down, I wanted to try to apply some protectant as a precaution. I've read that scotch guard is essentially useless and that the only effective method is some sort of "Fluorochemical and Acid-Dye" solution. Does anyone have any experience with this product/process? What to use... how to use it? Thanks in advance!