Sorry about the lack of details, my little guy (20 months old) was trying to rough house with me while writing this up. I started with a light emulsifier in the cimex while shower feeding it onto the slate. Then I used our tile wand to clean at around 500psi. Did not need to be stripped. Used my battery pump sprayer for the pure solvent sealer (I believe advanced?) it was about $160 a gallon and used the microfiber mop to spread it evenly on the tile. Learned a lesson, don’t use battery sprayer for this, almost ruined it. Customer was extremely pleased with the final results and so was I.