Blue stone help needed

[marinegrunt]

Blue Stone

Hey guys, was at a customer’s home this afternoon and he asked if tomorrow when we come back to clean his exterior glass if we could clean his back patio. He wasn’t sure of the type of stone and the search bar isn’t bringing me to any results with anything that looks similar. Anyone familiar with the stone? Seems like pretty tough stuff. What would you recommend to clean? DS house wash mix or maybe up to straight ds? Also would you just let dwell and rinse or bust out the sc? Will be digging thr…