I want to use the Behr Concrete Dye kit from Home Depot. The existing concrete at one time had paint spilled on it and carpet glued down. The concrete floor was poured back in the 1980's and , of course, was never intended to be seen (covered by carpet). I have patched the holes left from the carpet nails and scrapped and sanded the glue spots but do I need to strip the paint off before applying the cleaner and etcher included in Behr's Concrete Dye kit?