We bought a house with existing saltillo tiles.It appears to have been stained dark brown, then sealed. It's worn off in many areas down to the original color.Tried stripping,but only takes off sealer.Want to get to original color, then seal.Can it be sanded, then sealed? Have been told it shouldn't be sanded. It's ugly as is!Any suggestions? Found someone who's willing to sand and seal, but nervous since it's 750 sq ft. of the house. Please help.